CP-E catted downpipe owners...

[AutoXRacer]

First of all, whats up with all the CP-E threads these days...? (lol2)

I finally got my fourth P0421 CEL...

P0421 = Warm Up Catalyst Efficiency Below Threshold (Bank 1)

The first one was when I newly installed the DP about three weeks later, then two weeks later, third one, one week later, and now just a few days apart.

I contacted CP-E and they requested pictures, I guess to make sure I had followed the install procedures regarding the 2nd O2 wiring. Their recommendation is for me to ship them the DP for a cat replacement. (bang)
You guys know how much of a pain it is to R&R that stupid part!! (notcool)

I tried for them to let my buy another one and just give me a refund when they get my old one...but no deal. :(
They said they can't sell my old pipe... I'm a little disappointed in this since it will cause my car to be down for an undefined period of time.

Have any of you CP-E catted DP owners had a cat fail on you...?
I'm thinking I should have gone cat-less now...(sad2)

[Darksun280]

hmmmm......seems like there slowly starting to bend you over......


your gonna be a pro at dropping and reinstalling that down pipe by the time this is all over LOL!

[chacon101]

So let me get this straight. You buy the part, it fails and now you just have to wait for them to ship you a new one while your car is down?

That sounds like horrible customer service. So what if you didn't have the stock pipe anymore? What if you didn't have another vehicle to use while you're waiting? What if a whole lot of things that all point to you be inconvenienced.

Instead of thinking you should have gone with a catless, I would be thinking that I should have gone with another company.

But what can you do now...they have you by the pipe.

[AutoXRacer]

So let me get this straight. You buy the part, it fails and now you just have to wait for them to ship you a new one while your car is down?

That sounds like horrible customer service. So what if you didn't have the stock pipe anymore? What if you didn't have another vehicle to use while you're waiting? What if a whole lot of things that all point to you be inconvenienced.

Instead of thinking you should have gone with a catless, I would be thinking that I should have gone with another company.

But what can you do now...they have you by the pipe.

The plan is for me to send them my failed catted pipe and it will take them two days turn around for me to get the repaired pipe. Communication has been +A. I understand their side though, but I might have as a business just sent out another pipe as long as the customer paid for it in advance and then refunded the amount as soon as I recieved the defective part.

But they are shipping it overnight I guess which is more than what other companies/vendors will do...

You have to give it to CP-E though, they are willing to do whats right or at least meet you half way...

I am not bitching or anything (blah), I am just trying to find out if catted DP owners have experienced this and how they handled it.

[meha11]

First of all, whats up with all the CP-E threads these days...? (lol2)

I finally got my fourth P0421 CEL...

P0421 = Warm Up Catalyst Efficiency Below Threshold (Bank 1)

The first one was when I newly installed the DP about three weeks later, then two weeks later, third one, one week later, and now just a few days apart.

I contacted CP-E and they requested pictures, I guess to make sure I had followed the install procedures regarding the 2nd O2 wiring. Their recommendation is for me to ship them the DP for a cat replacement. (bang)
You guys know how much of a pain it is to R&R that stupid part!! (notcool)

I tried for them to let my buy another one and just give me a refund when they get my old one...but no deal. :(
They said they can't sell my old pipe... I'm a little disappointed in this since it will cause my car to be down for an undefined period of time.

Have any of you CP-E catted DP owners had a cat fail on you...?
I'm thinking I should have gone cat-less now...(sad2)

I had this exact same problem.
The new cat is a different brand (made in Canada). No issues since installing the new part.

[AutoXRacer]

I had this exact same problem.
The new cat is a different brand (made in Canada). No issues since installing the new part.

So did you have to send them your DP?
I purchased/installed my DP back in Jan 08...I wonder when this updated/new cat came into effect?

[Captain KRM P5]

i am betting if you use a single spark plug non fouler to extend the secondary sensor outside the downpipe you would be rid of this code

[Mid_Life_Crisis]

i am betting if you use a single spark plug non fouler to extend the secondary sensor outside the downpipe you would be rid of this code

It might get rid of the code but, if the cat is bad, it still needs to be replaced.

[AutoXRacer]

i am betting if you use a single spark plug non fouler to extend the secondary sensor outside the downpipe you would be rid of this code

True, but then what was the purpose of spending an extra $330 for a catted DP...?
I would have bought the Cork Sport DP instead... I wanted a functioning cat... (scratch)

[meha11]

So did you have to send them your DP?
I purchased/installed my DP back in Jan 08...I wonder when this updated/new cat came into effect?

Yes i sent it back, i had my car up on ramps for a month while they sourced a better cat.
From what Josh said i was the first to report this issue so hopefully it wont be as long for you.


For visuals-
http://www.mazdas247.com/forum/showthread.php?t=123646848&page=46

[meha11]

Just to clarify, i my first post i mentioned "new cat" meaning MY NEW CAT. I dont know if they use this in their production, post to my issue.

[AutoXRacer]

Just to clarify, i my first post i mentioned "new cat" meaning MY NEW CAT. I dont know if they use this in their production, post to my issue.

I'll ask Josh... Thanks (2thumbs)

[dparm1984]

It's possible it could have failed from a rich condition over a long period of time. Motors that run rich (like the DISI we have), will often dump unspent fuel into the exhaust manifold. This then detonates in the manifold or cat and slowly eats away at the catalyst brick.

I had this happen on my old car -- was running some big-tube headers without a tune, and over time the catalytic converter packing material burned up.

[Dream]

i am betting if you use a single spark plug non fouler to extend the secondary sensor outside the downpipe you would be rid of this code


THIS! I cost's about 2 dollars at the hardware store.

[dparm1984]

If the problem is becoming more frequent, I think it's more important to isolate the cause rather than keep band-aiding it.

[meha11]

here is a picture of the old cat. B-Tiger appears to be the brand name.

[AutoXRacer]

here is a picture of the old cat. B-Tiger appears to be the brand name.

Darn it!!! Mine has Louis Cat stamped on it... I wonder if thats the Canadian cat.

[SilverWagon]

Hello all, this is my first post! I was looking at this full turbo back exhaust. I found it to be a little pricey but figured you gotta pay to play. After reading this thread i def will not be going with this. To pay 700 dollars for a downpipe and have issues with it is absurd! Looks like im going back to the drawing board.....(wow)

[meha11]

Darn it!!! Mine has Louis Cat stamped on it... I wonder if thats the Canadian cat.

Look at both pictures side by side, i think they are the same despite the different names. It looks like both say BT-P-07003M- Dont know what that means.

The only reason i know my replacement is made in Canada is because it is stamped on it. It also looks different (wider but shorter).

Ask for the Canadian Cat, chances are it was built in a Union shop, I'm not for unions but when buying something, if i have the choice between 2 products otherwise the same i would go union built.

(wow I think this is a record for me, 6 post in 1 day, I need to slow down before my posts/day goes over 1).

[AutoXRacer]

Look at both pictures side by side, i think they are the same despite the different names. It looks like both say BT-P-07003M- Dont know what that means.

The only reason i know my replacement is made in Canada is because it is stamped on it. It also looks different (wider but shorter).

Ask for the Canadian Cat, chances are it was built in a Union shop, I'm not for unions but when buying something, if i have the choice between 2 products otherwise the same i would go union built.

(wow I think this is a record for me, 6 post in 1 day, I need to slow down before my posts/day goes over 1).

Yep, its the same part number as yours!!!! Just difference company? <weird>
I emailed Josh...still waiting for a reply. We'll see what he has to say.
Thanks for the info though!!! (2thumbs)

[Captain KRM P5]

True, but then what was the purpose of spending an extra $330 for a catted DP...?
I would have bought the Cork Sport DP instead... I wanted a functioning cat... (scratch)

the cat is probably functioning fine for its design. i'm betting its not functioning well enough for the o2 sensor's preferences more than anything else.

got your pm/email working on it

[SilverWagon]

The whole purpose of a cat in my mind is to pass emissions and keep cels away. If this cat throws a cel, it certainly will not pass emissions, so what exactly is the point of it?

[Darksun280]

Yep, its the same part number as yours!!!! Just difference company? <weird>
I emailed Josh...still waiting for a reply. We'll see what he has to say.
Thanks for the info though!!! (2thumbs)

good luck hope everything works out

[Kosh]

Do any other companies make a catted dp's for our car? Don't feel like running DSP.

[AutoXRacer]

Do any other companies make a catted dp's for our car? Don't feel like running DSP.

Nope!! (no)
Thats why I was stuck buying a CP-E... What I really wanted was the Cork Sport, but they have no cats!!

[meha11]

the cat is probably functioning fine for its design. i'm betting its not functioning well enough for the o2 sensor's preferences more than anything else.

got your pm/email working on it

Maybe however this TBE was designed for this car and the cat is integral to it's design. The only acceptable outcome is for the exhaust to work as designed and advertised by the manufacture and its distributors. In this case i have no doubt cpe will correct the issue.
I realise your defending a product that you sell and that’s good, however the Cat is clearly no good, whether it be faulty or used in the wrong application is irrelevant, it needs to be replaced.

[redrocketz]

NO CATS FTW

if it is from Canada I am willing to bet it is Vibrant.

[AutoXRacer]

NO CATS FTW

if it is from Canada I am willing to bet it is Vibrant.

I wish NO CATS FTW... But I don't like my interior smelling like raw fuel or having to suffocate drivers behind me... Been there, done that... (lol2)

[User Name]

I know a few of us have emailed Corksport about putting out a catted dp and/or mp. If more people bug them about it, the more likely they are to make it.

[redrocketz]

the thing is with the design of their downpipe there is NO way you could add a cat to it. and in the mid pipe it would be too far downstream without some O2 extensions.

[Kosh]

I guess you could always go to an exhaust shop and get a custom tbe with high flow built. Wonder how much that would cost.

[aaronc7]

I know a few of us have emailed Corksport about putting out a catted dp and/or mp. If more people bug them about it, the more likely they are to make it.

Yeah, they said it would probably take some time to get things going...so I'm just going to have one welded into the mid pipe. The second O2 on the DP just has a spacer to trick the computer somehow...no idea how that works lol

[Paula@cp-e™]

Folks with our downpipes, thanks for chiming in. I just wanted to jump in and mention a few points.

First of all, we're doing the best we can with what we've got. We're a very small shop in Maryland (not a multi-million dollar company), and we try to meet people in the middle with situations such as this. We're honoring the warranty, and we'll correct the problem. The fact is that most aftermarket companies follow this return procedure, let alone one as small as ours. It sucks, but in the rare case that a downpipe cat goes bad this is unfortunately a necessary evil. Thankfully AutoXRacer has been incredibly understanding, so we thank you sincerely for that!

We also don't manufacture the cats. We tested four different cat manufacturers trying to find the best one for the job, but if the brand we selected is not operating properly then we'd like to know about it so that we can notify the manufacturer so they can rectify their end of things. So thank you for bringing this to our attention immediately! And for whatever it's worth, those cats are not a "Louis Cat," it's a "Kooks Cat", which is sold by Kooks Custom Headers; a very reputable exhaust manufacturer in NY. So it was a quality, name brand cat:

http://www.kookscustomheaders.com/

I'd also like to mention that for every person who chimed in here that had an issue with our downpipe, there are dozens who haven't had any issues at all. So I'd like people to try to keep things in perspective. We make one of the most popular downpipes on the market, and I think one or two isn't unreasonable. OEM parts fail occasonally, no?

If we weren't fixing these issues I'd understand the frustration, but AutoXRacer, we'll get you where you need to be buddy (drinks)



NO CATS FTW

if it is from Canada I am willing to bet it is Vibrant.


It is not a vibrant cat, nor is it made in Canada. The catalyst is manufactured in the US, but the stainless steel used to spin the case is made in Canada, FYI.

[SPEED3TYPE2]

I'm going to get the cp-e down pipe as soon as I get the money, i've read to many good things about the quality of the products, nothing is prefect al products will have a few bad apples..

[staples187]

I've had the turboback with the high flow cat on my car for 8 months now. I have not had a single problem *knock on wood* yet. Have you ever considered the 02 sensor not sitting or being properly installed? The downpipe has been out for over a year now including the catted version and this is the first story I've heard about throwing CELs. How long did you have it for before you threw a code? Have you ever shot a flame or had backfire?

[ispypsi]

hope it works out autoX, looks like cp-e is trying their best to help you. i would still prefer the new option, since they'd have to hack up your old one anyways, don't see why they couldn't just sell it back off as used for slightly less to someone else (i know someone else wouldn't mind buying a slightly used one with the updated cat put in it).

i would definitely pay to buy a test/race pipe version with a cat in it, and would allow me to buy the corksport downpipe. if someone offered that piece of the exhaust in 3" with a high flow cat and some extensions for the o2 sensors, i'd be down for that. i would assume people who are worried about cats could buy the corksport downpipe, then fab up their own catted mid section pipe. i havnt been under the car, so i don't know the issues with the lengths of wire on the o2 sensors, but i dont see them being that hard to extend. o2 sensors usually don't use shielded wire or anything fancy.

[staples187]

hope it works out autoX, looks like cp-e is trying their best to help you. i would still prefer the new option, since they'd have to hack up your old one anyways, don't see why they couldn't just sell it back off as used for slightly less to someone else (i know someone else wouldn't mind buying a slightly used one with the updated cat put in it).

i would definitely pay to buy a test/race pipe version with a cat in it, and would allow me to buy the corksport downpipe. if someone offered that piece of the exhaust in 3" with a high flow cat and some extensions for the o2 sensors, i'd be down for that. i would assume people who are worried about cats could buy the corksport downpipe, then fab up their own catted mid section pipe. i havnt been under the car, so i don't know the issues with the lengths of wire on the o2 sensors, but i dont see them being that hard to extend. o2 sensors usually don't use shielded wire or anything fancy.

You're right. You actually have to extend the 02 sensor for CPEs downpipe anyways.

[Captain KRM P5]

I'm going to get the cp-e down pipe as soon as I get the money, i've read to many good things about the quality of the products, nothing is prefect al products will have a few bad apples..

quite right. i've been very happy with the quality i've personally seen from cp-e's products that we've sold.

[AutoXRacer]

I've had the turboback with the high flow cat on my car for 8 months now. I have not had a single problem *knock on wood* yet. Have you ever considered the 02 sensor not sitting or being properly installed? The downpipe has been out for over a year now including the catted version and this is the first story I've heard about throwing CELs. How long did you have it for before you threw a code? Have you ever shot a flame or had backfire?

The O2 sensor is properly installed and wiring extended. It threw a code about two to three weeks later. And the frequency has been increasing. Though, I haven't had one since Sunday...
(huh)
I would prefer not to have to go through all of this R&R...

Here are some pictures of the O2 sensor install.

http://i44.photobucket.com/albums/f19/Milkywayman22/Mazdaspeed%203/CP-E%20Downpipe/DSC02542.jpg

http://i44.photobucket.com/albums/f19/Milkywayman22/Mazdaspeed%203/CP-E%20Downpipe/DSC02552.jpg

http://i44.photobucket.com/albums/f19/Milkywayman22/Mazdaspeed%203/CP-E%20Downpipe/DSC02541.jpg

[knowledge007]

I didn't extend anything. I used two of the wiring harnesses that hook up to the heat sheilds and ran them through there in order to keep them away from the exhaust. My Mazda mech came up with that idea and it worked like a charm.

[staples187]

Doesn't look like there's an problems with the sensor installed wise. I could only imagine it's the actually cat on the downpipe especially if you're throwing that particular code. Ahh sorry to say, I know it's a bitch to pull it off and the downtime on the car.

[AutoXRacer]

Doesn't look like there's an problems with the sensor installed wise. I could only imagine it's the actually cat on the downpipe especially if you're throwing that particular code. Ahh sorry to say, I know it's a bitch to pull it off and the downtime on the car.

Tell me about it!! (bang)

Oh well, at least CP-E is going to fix it... (2thumbs)
I guess one must expect things like this to happen when you start altering/modifying a car... (lol2)

[Mid_Life_Crisis]

Downtime? You didn't keep the original parts "just in case"?

Still a major headache with the parts in and out thing, but at least you'd be driving.

[knowledge007]

original exhaust, shit I cut that crap out and threw that sucker in the garbage. Only kept the first cat in case someone needed a stock cat with less than 10k on it.

[AutoXRacer]

Downtime? You didn't keep the original parts "just in case"?

Still a major headache with the parts in and out thing, but at least you'd be driving.

I have all my stock parts, but I am not installing the stocker back...its a nightmare. Plus, I'll be leaving on a business trip while the car is down.

[knowledge007]

Why are you doing that Auto?

[AutoXRacer]

Why are you doing that Auto?

Doing what? (huh)

[knowledge007]

goind back to stock?

[Mid_Life_Crisis]

goind back to stock?

He is not going back to stock. It appears that his downpipe has a bad cat so he has to take it out and send it back to be checked out and fixed if it is.
I asked if he has the stock parts so he can drive the car while his DP is gone.
He does, but he has no interest what-so-ever in going back to stock even temporarily and fortunately does not have to because he will be out of town while his car is out of commission anyway.

[camrycev6]

Folks with our downpipes, thanks for chiming in. I just wanted to jump in and mention a few points.

First of all, we're doing the best we can with what we've got. We're a very small shop in Maryland (not a multi-million dollar company), and we try to meet people in the middle with situations such as this. We're honoring the warranty, and we'll correct the problem. The fact is that most aftermarket companies follow this return procedure, let alone one as small as ours. It sucks, but in the rare case that a downpipe cat goes bad this is unfortunately a necessary evil. Thankfully AutoXRacer has been incredibly understanding, so we thank you sincerely for that!

We also don't manufacture the cats. We tested four different cat manufacturers trying to find the best one for the job, but if the brand we selected is not operating properly then we'd like to know about it so that we can notify the manufacturer so they can rectify their end of things. So thank you for bringing this to our attention immediately! And for whatever it's worth, those cats are not a "Louis Cat," it's a "Kooks Cat", which is sold by Kooks Custom Headers; a very reputable exhaust manufacturer in NY. So it was a quality, name brand cat:

http://www.kookscustomheaders.com/

I'd also like to mention that for every person who chimed in here that had an issue with our downpipe, there are dozens who haven't had any issues at all. So I'd like people to try to keep things in perspective. We make one of the most popular downpipes on the market, and I think one or two isn't unreasonable. OEM parts fail occasonally, no?

If we weren't fixing these issues I'd understand the frustration, but AutoXRacer, we'll get you where you need to be buddy (drinks)





It is not a vibrant cat, nor is it made in Canada. The catalyst is manufactured in the US, but the stainless steel used to spin the case is made in Canada, FYI.

I didn't know you guys were in MD. I might have to stop by and check out your shop. I was 100% against a warranty perilous mod, but with you guys being so close, I could always come back if there were any issues.

[AutoXRacer]

He is not going back to stock. It appears that his downpipe has a bad cat so he has to take it out and send it back to be checked out and fixed if it is.
I asked if he has the stock parts so he can drive the car while his DP is gone.
He does, but he has no interest what-so-ever in going back to stock even temporarily and fortunately does not have to because he will be out of town while his car is out of commission anyway.

(iagree)


goind back to stock?

Yeah, what Mid Life said (blah)... (lol2)

Damn, I'm starting to look around for cameras and bugs... :D

The stock piece is more complicated to install, you got the DP, mid pipe, and brackets... More importantly, I'd have to R&R the O2 sensors twice...and seeing how they damage so easily...no thanks (no)

I am already dreading and paranoid about having to remove the O2 sensors...

[mazdaspeedjay]

AutoX Don'ty stress so much about the O2 sensor unless you already screwed them up the first time. i work for mazda as a tech at a dealership an i did a nice write up on how to remove the o2 sensors without screwing up the threads. it's a big problem everyone at mazda and any tech thats tried to remove them knows it and by going by my write up in the how to section on how to remove and fix the problem i have removed many o2 sensors since my first and have yet to screw up any threads and this includes using my own car as a guine pig to find the best way. my car had only 4,000 miles on it when i fix my sensors and if i didn't do it write i would have messed up the threads. so try not to stress about that one thing. read my write up use plenty of pb blast or simulair oil and be patient but you've already removed it once so you might need to go out and buy a nice thread caser and tap and die to fix them.

well i live in maryland and i'm looking at getting cp-e's DP only because they are the only ones that use cats and like autox i'm someone that doesn't want to smell raw fuel and have to worry about throwing a cat. code or dtc i ran no cats on my srt4 and i swore i'd never do it again. people fail to relize is that 3" down pipes have been dyno'd with and without cats or running high flow cats and there was only like a 5 HP difference in running a cat or no cat. this was dyno tested and only got 5 HP more without running a cat converter. to me 5 HP is nothing to worry about so i'll go with the cat option.

I installed a turbo x's down pipe on my buddies speed 3 and sure enough even with their second o2 sensor bung being extra long acting like a spark plug fouler three days after i installed it it threw a CEL for cat. effiency. WTF ? I told him he needs to call turbo x's right away and ask them why it's throwing that code when it shouldn't and everything was installed using there crap ass instructions or lack there of. I love cork sports DP and really like the seperated gas flow design but still not sure if i want to go catless cause as of now i want to run a cat. luckly i live in maryland so if i do go with cp-e and have this problem i can easy just drive down there and deal with them directly.

I know this sucks but i've met some guys that work for cp-e a while back and they seem like cool people and they have gotten on here and stated that they're willing to fix the problem so it sucks yes but it's still better then them saying hey tough luck your loss. keep us updated please

[AutoXRacer]

Weird update...

I haven't gotten a CEL in a week... What gives? (huh)
I'm starting to think whether I should R&R the DP or not now... I wonder if its temperature related. All the times the CELs have gone off was an in between temp of not really cold, but not warm either... I don't know how to explain it....

I don't know what to do now... I'll give it till next Monday, since I leave for my trip on Wednesday the 12th and I was planning to R&R it on Tuesday before my trip.

[knowledge007]

Auto, I had a CEL for the same thing approx. 2 months in. I reset the ECU and it has never come back. It has almost been a year. Give it some time, I think its just the stock ECU messing with us.

[AutoXRacer]

Auto, I had a CEL for the same thing approx. 2 months in. I reset the ECU and it has never come back. It has almost been a year. Give it some time, I think its just the stock ECU messing with us.

I don't know, I've reset the computer a few times already; when I installed the DP and another time when I installed the TMIC...

I think I might give it more time if I don't get one before I leave...

[palerider]

I dont understand why there arent more guys running the Vibrant downpipe-back exhaust with the included cat. It is an option for those guys wanting to have a highflow.

Im not saying its a better setup than CPEs but the CS downpipe with the Vibrant dpback is a pretty sweet setup for the money if you ask me. Two exhaust parts, with a divorced wastegate, hiflow cat, GREAT sound, and GREAT price.

I know Ken was offering the whole TBE package of these two together, at 899 shipped at one point. I just dont think you can beat that.

[knowledge007]

I like the material used on the CP-E's product. .304 stainless steal. No coated like the exhaust you have mentioned if I am not mistaken. I know I paid out the ass for this system, but IMO it was well worth every penny.

[Mid_Life_Crisis]

I dont understand why there arent more guys running the Vibrant downpipe-back exhaust with the included cat. It is an option for those guys wanting to have a highflow.

Im not saying its a better setup than CPEs but the CS downpipe with the Vibrant dpback is a pretty sweet setup for the money if you ask me. Two exhaust parts, with a divorced wastegate, hiflow cat, GREAT sound, and GREAT price.

I know Ken was offering the whole TBE package of these two together, at 899 shipped at one point. I just dont think you can beat that.

Does this include "cheaters" for the O2 sensors or some way to relocate them to the replacement cat?

[Mid_Life_Crisis]

Yeah, what Mid Life said (blah)... (lol2)

Damn, I'm starting to look around for cameras and bugs... :D


While you watch your TV, who's to say your TV isn't watching you...

[mazdaspeedjay]

i've seen that vibrant system where it's a dp back exhaust basicly you are buyin a dp back exhaust and they're throwing in a test pipe for free. i just don't know about vibrant as far as their quality. in my experience and this is just mine vibrant is kind of a APC like company. BUT they've managed to stay around when others have gone out of business so that has to say something for the company. sorry to say i won't be the first on that one i'll wait for someone else to do that and i like others better. as of now corksport has the largest system out there at 80mm converted to inchs if my converter is right thats 3.14 " 's just slightly larger then 3" but i don't think that makes that big of a difference.

I was at the drag strip this past sunday and there was three speed 6's up there running Cp-E turbo back exhaust aLL has single tips. two were cat-less and one was catted and all have had theirs for about a year now and all said they've had no CEL's at all even the ones with no cat's. they sounded very very nice i might ad. i need to take a ride down there and check them out they're only like thirty minutes from my house.

[dparm1984]

I wouldn't really buy on a brand name anyways...buy based on the objective points of the product. Who cares if Vibrant makes it -- if it's stainless and fits right, and the specifications match another company, it's probably not different.

I admit that I don't entirely trust Vibrant, but it does speak volumes when you see how long they've been around. They must be doing something right.

[AutoXRacer]

I found out what the part numbers are on the MS6/ MS3. the numbers depend on the manufacture date of the car, but both the turbos are having problems.

L3R9L3700F (most 06 models, and some 07 models.
L3Y11370Za (replacement for the 06 turbo, and OE for most 07 models)

I've also found that part of the issue might be related to EGTs being a little hotter.

I was also told by the local dealer that they have been instructed not to do any work on the turbos unless the exhaust is stock except for a different muffler. He showed me the email from MNAO. All I can say is be really careful with what you do to these. They are pretty well tuned from the factory.

Some hope I have had though is I switched brand of oil from full synthetic vavloline to Royal purple, and it hasn't had the same amount of smoke.

You can also run you car through a defoul mode. to do this make sure you parking brake is set. Turn all accessories off. leave it in neutral. Press the gas down, and hold the RPMs in the 3500-4000 range for about 2-3 minutes. When it's done the car will return to idle on it's own. When it does take you foot off the gas pedal. By the way make sure you don't have the exhaust blowing on anything. It's going to get really hot.

If anyone has seen GM do it on on the newer duramax with full exhaust done it'll start thing on fire within seconds. Most I've gotten my MS6 to do was burn the hell out of my friend's leg

Part of the problem is also the first cat on the car. it collects a ton of junk in it, and the defoul mode that is supposed to come on during highway drives helps clean it out.

The quote in red would explain my issues with the irratic P0421 CEL...
I still (knock on wood) haven't gotten a CEL...

I wonder what this "defoul mode" does to the high-flow metallic cat...?