I drive a 03 OZ rally. I purchased and installed a Greddy ti-C cat back approximately 4 months ago. About a month ago my CEL came on. I figured it was a bad o2 sensor and it was. However my mechanic told me that the code was for the o2 sensor and that was what was turning the CEL on but there was nothing actually wrong with the sensor it's self. He thinks it is the back pressure of the catback now that it has been covered in carbon. He said i could replace the o2 sensors to fix the problem so i could pass inspection but more likely then not the CEL problem would just come back. Has anyone encountered this problem before or know a way to fix this permanently with out replacing my cat back?

Thanks

 

You could always get the CEL eliminator from RRM.

http://www.roadracemotorsports.com/s...products_id=36

 

thanks man ill email rrm and see if they think that will fix my issue

 

bump i don't think that will fix the issue

 

What's the code?

 

I have a cat-back exhaust and haven't had that problem at all. I've had it for about 6 months now at least too...

do you done anything to your computer or fuel injection system? if you're running rich that would more than likely kill the o2 sensor

 

nope just the cat back...i did put in new plugs but i don't see that causing an issue... maybe my sensors are just junk ..i m gonna try the non-fouler cheat tomorrow and if that doesn't work ill get new sensors

my mechanic didn't tell me what the code was i'll have to call him and ask him he just said the o2 was trigering the cel but there was nothing wrong

 

Don't beleive anything your mechanic tells you before you get our opinion
Drop by Autozone or something, get the code and come back here

 

I'll need to grab my code, because my code won't go away either. It pretty much resets itself occasionally, but it doesn't stay off.

 

I have not had a code at all on my car for over a yr and a half ! lol
And i have Header/Downpipe/Stock Cat/ Evo2 Catback.

You may have a a bad cat !

Go to Autozone and tell them tyo pull your code . Then i would be able to help you pinpoint the problem !

Good luck ,
Antonio .

 

I have full 2.5" exhaust...sooooo...

 

lol i got the codes they are P0135 (bank 1 sensor 1) and P0135PD (bank 1 sensor 2)
i was told this is a general "o2 sensor not working" code

 

could it be a plugged cat?

 

ended up just being the oxygen sensor...he took back all that crap he said about my exhaust being the issue and was like "yea of course your o2 is broken" after a week of me exploring all possible problems and being like it seems like it is just the o2

thanks though guys for your help lol

 

Are you serious? you just needed a new O2?