Hi-Flow Cat & Check Engine Light

[CantCMe]

About 18 months (and 110,000 on the odo) my check engine light came on in my '02 ES. The "stealership" told me I needed a new ($1200!!) catalytic converter. Instead I went to an exhaust shop and had a hi-flow cat and custom 2.25' exhaust w/ an APEX muffler installed. The check engine light dissappeared for about a week, then it comes back. It would stay on for a week, then turn off for a week. After about a month of this, it would just stay on. I've recently taken it back to the exhaust shop (so I could get through emissions) and they say that something with the motor is making the cat go bad. Mind you the motor is stock other than an AEM intake. They say that they'll give me another cat for free but just charge me for labor (about $140) but the warranty for the old cat and the new one is only 90 days!!! So there is a chance that I'll run into this little problem again. This morning I went through emissions with flying colors while the engine light was off but I'm not trying to switch converters every other month. Has anyone outh there run into this problem with a hi-flow cat or is it this particular shop doesn't know what the hell they're doing?

[njaremka]

to PROPERLY diagnose a CEL, you need to get the code. without the code, its a crap-shot at best.

[CantCMe]

I can't remember the code right off, but they said it was a code for a bad cat, but I can't think of what could be making the converter go bad. It's almost bone stock.

[ChopstickHero]

you need to get the code read. it could be your secondary O2 sensor (the one by the second cat) that could have some problems.

[CantCMe]

you need to get the code read. it could be your secondary O2 sensor (the one by the second cat) that could have some problems.

I'll have them check that also. I'm wondering why when people charge you a certain amount for a diagnostic test they just don't check EVERYTHING involved with the problem. They're just losing customers...if I can't get it straight, I'll start from scratch with a new cat and exhuast from a better shop.

[njaremka]

if the dealership was reffering to the primary cat, and you took the car to another shop and had the secondary cat replaced, then its your fault.

[CantCMe]

You're right...believe it or not, I didn't even know it HAD two cats on it. I'm going to have to look under the car to find out. All the dealership said was I needed a catalytic converter, and the shop "supposed" to have replaced it with a hi-flow cat. But "when" I start from scratch, I'll have it done right this time.

[njaremka]

just get a header and an o2 "fix" set-up, then, good-to-go

[CantCMe]

what's the best header to get? and what's the 02 fix?

[njaremka]

OBX, and...

http://www.mazdas247.com/forum/showthread.php?t=123634664

[CantCMe]

thanks...i'll be doing this very soon.

[mickeyreategui]

thunder, fits good, and no cel and no primary cat!!!!

[CantCMe]

Well, new day, new problem...I know the exhaust place I went to is horrible now...the muffler was draggin' so bad i just yanked it off!! So what I plan on doing now is getting a hi-flow cat AND complete exhaust plus a header. Anybody know which ones I should get? Hopefully I'll be getting everything by next weekend if I can get the stuff AND get a good place to get it installed.

[Shift2xlr8]

Well, new day, new problem...I know the exhaust place I went to is horrible now...the muffler was draggin' so bad i just yanked it off!! So what I plan on doing now is getting a hi-flow cat AND complete exhaust plus a header. Anybody know which ones I should get? Hopefully I'll be getting everything by next weekend if I can get the stuff AND get a good place to get it installed.

I personally have had both the fart can exhaust and the quieter Borla, and overall hands down I love my Borla a lot better, and its a lot more performance aimed, I gained a lot more torque out of mine over the fart can. I'd say it sounds similar to a 350Z with a exhaust on it. As for the hi flow cat, I don't know about those, I personally don't have one, but may invest in one sooner or later. Ive heard rumors that the MAM mid pipe is a good investment, however I don't see spending $150 on a piece pipe with flanges on the ends as a good investment. But who knows.

[CantCMe]

I forgot all about the midpipe...someone over the weekend told me about getting a Borla exhaust for my car. The same person told me about an OBX header. I see alot of hi-flow cats for about $150-200 which isn't bad-as long as I don't have to go through the damn CEL coming on! Does Borla sell midpipes for Protege's?

[Shift2xlr8]

The Borla I have came with a cat back system and it has a resonator on it, but I didnt install that part of it because my cat was welded in, so it would have been too much work to cut the back of the cat's pipe and weld in 2 flanges and then attach them together...I was trying to go with the cheaper route, but still wouldnt lose any HP/TQ. I run the factory cat, and the Borla muffler, with a Tsudo 4-2-1 header. Yes my check engine light comes on but if you use this link:

http://www.mazdas247.com/forum/showthread.php?t=123634664

Then you wont have any problems. When I put my header on it eliminated the pre-cat and thats why the CEL came on. I bought the spark plug non flouers and plan on putting it in this weekend or sometime this week after work. The CEL code should say something about your catalyst reading too much emissions, so its going to run really rich for a while until you do the plud fouler. My buddy Dustin and I leaned down my fuel rail with the factory fuel pressure regulator so that my gas mileage wasnt so shitty, Ive been filling up every 4days or so, but I also drive my car somewhat rough, but before the header it was never that bad. If you do turn the fuel down and lean it out, you will get a little bit better MPG and you will notice a lot more lower end torque, I did and the car runs great, even with the CEL still on, I cant imagine what it will run like with the CEL off. Ill have to more than likely turn it back up and run a little more rich so I dont blow something. Hope that this wasnt too confusing for you if you have any questions feel free to post them or PM me with them.

Chris

[CantCMe]

Thanks for that...I'm gonna go the non-fouler route. I'm sure this other exhaust shop will do a better job then the last one.

[Shift2xlr8]

Hopefully, good luck. Like I said before, no sense to go spend hundreds of dollars on a piece of pipe with a muffler attached to it when you get buy the muffler for 50-75$ and then just have the extra cash and get the same performance from it.

Chris