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Ch555
09-22-2009, 12:16 PM
Hi what happens if i remove second cat on my 2.0 2001 protege? My front pipe connections broke and i thought that i change my 2nd cat to that flexi pipe, if u know what i mean :) And there are no O2 sensors after that cat. Only before and after 1st... Other bad thing is that there are no aftermarket front pipes available, so i have to repair it somehow :confused: Any ideas? :)
ucMP3
09-22-2009, 02:05 PM
There are aftermarket front pipes available. But you can just go to a muffler shop and have them weld a new cat in or they may weld in a straight pipe if they either don't care about legal issues or you do them a special favor ;)

You don't need to put a flex pipe in unless you are replacing your front pipes with ones that don't flex at all. The spring bolts and multi-piece system that is used from the factory provides enough room to move.
MaxPower
09-23-2009, 06:51 PM
1. Walker makes a replacement catalytic converter you can buy (try RockAuto.com). It's about $250.
2. You can purchase a used J-pipe (front pipe) online here for very cheap. Post a want-to-buy. New, it will cost about $250-300 with the springs, nuts, gaskets, etc. from Mazda.
3. You can also buy a used 2nd catalytic converter on this forum.
Ch555
09-24-2009, 12:55 PM
Got it repaired today, all good. Anyway had a thought. If i by e-bay header (?) it removes 1st cat. So my cel will light up. But, will it work if i made a new hole after the 2nd cat and put the lambda there? So there will be one sensor on the header and another after 2nd cat.
ucMP3
09-24-2009, 03:11 PM
No, it won't get a proper reading. There are 2 easy fixes to avoid throwing a cel tho. Search for "Mil Eliminator" and it should pull up both. One method uses a wired resistor to fool the ECU and the other relocates the O2 sensor back about an inch from the exhaust pipe in order to fool the ECU. I used the 2nd when I removed my stock system and I haven't had a CEL once.
Ch555
09-25-2009, 04:31 AM
yea i know those options, but i fail my MOT without cat...
ucMP3
09-25-2009, 08:07 AM
What is MOT?
Zoomzoom17
09-25-2009, 08:48 AM
Just remove it and throw like a Cherry Bomb in it's place, adds a nice sound.
ucMP3
09-25-2009, 10:27 AM
Just remove it and throw like a Cherry Bomb in it's place, adds a nice sound.

"nice" is an interesting description. :D
Zoomzoom17
09-25-2009, 11:44 AM
"nice" is an interesting description. :D
Okay well it's not going to be an amazing sound like a full cat-back exhaust but it's still going to be a low grumble. Just grow in a Cherry Bomb Glasspack if you're taking it out. Plus I'm not sure on Older Protege's if it'll pass emissions without a second one. Or am I not making sense?
IukekiniProtege
09-25-2009, 12:08 PM
The federal emission cars came without a second cat. This is how my new 00 ES is, the old one was cali. emissions and had two cats. So removing it wont harm anything, unless your state does a sniffer test on the exhaust, and even still the first cat should be good enough to pass that.
Ch555
09-25-2009, 01:47 PM
ups... srry didnt realise us may have another name for it (hand)
http://en.wikipedia.org/wiki/MOT_test
ucMP3
09-25-2009, 01:56 PM
O, sorry I didn't notice your location. I figured you were talking about that I just wasn't sure. If its an OBD2 test, you will be fine as long as you are not throwing a CEL (and haven't for I think 300 miles). But, a sniffer test and/or visual inspection may give you a fail without a second cat.

I personally have no 1st cat, and my 2nd cat is a hi-flow so it's a good thing Ohio hasn't had emissions testing for about 5 years. :D Whenever they bring it back around (I hear it won't be much longer) I will have to figure something out. Probably will jsut have to start stalking someone who works there and conveniently become friends with them, so they will pass me :)
Ch555
09-25-2009, 02:32 PM
ye, we have all that - visual test and some kind of probe sticked into the exhaust (ouch) (lol2) Ok i think i can remove second cat, if i keep 1st. Then i shall pass my test. But is it worth to remove 2nd? Is there any noticeable gain in power. I have already impreza sti bacbox. Someone told that cat takes away ~5hp ?
slavrenz
09-25-2009, 11:46 PM
The federal emission cars came without a second cat. This is how my new 00 ES is, the old one was cali. emissions and had two cats. So removing it wont harm anything, unless your state does a sniffer test on the exhaust, and even still the first cat should be good enough to pass that.

The 2.0L Proteges (2001 and up) all came with 2 cats.