just had my 3 inch megan racing downpipe, helix 3 inch hi-flow cat, and megan racing catback exhaust installed and after about 1 week the car threw this code...think its a one time thing or will this continue to happen? is there a fix? maybe with dynoflash or one of the others taking into account my new exhaust? will this affect performance at all??

any info would be great thanks!!

 

Its the High flow cat and yes there is a flash for it out there. It shouldnt affect performance, the cel just goes on when there is a big difference between the the two sensors. It might go off, but will just probably stay on untill you replace the high flow cat or get a reflash.

 

I thought the light comes on when there ISN'T a big difference between the before and after cat O2 sensors? ie....no difference in the readings = a catalytic converter that isn't scrubbing the exhaust properly. But I could be wrong.

SC~

 

I believe this is correct.I have the same SES light on. It always comes on the second engine start after I disconnect the negative on the battery. Al said he wont fix this code from returning. It is normal on cars with a high flow cat and the only fix is to modify the rear O2 sensor in a way that it doesn't see all the exhaust flow anymore so the car thinks the cat is scrubbing most of the exhaust cleanly.

My 2 cents

 

ok well im not so concerned, but when you do have a check engine light on, does the car automatically slow down performance... retard timing or whatever because it thinks something is wrong with the car? thats when i would care....

 

I think it does! The computer would probably run leaner and retard timing, in the effort to prevent Cat meltdown. the computer doesn't know that the cat is missing. Just get an O2 simulator.

 

whats an o2 simulator and who makes one/where would i get one?

forgive me if im being retarded.

 

I was told it doesn't affect the computer at all. Its in another thread somewhere around here

 

This problem has come up many times.

Check this thread for an easy mechanical solution:

https://www.evolutionm.net/forums/sh...ad.php?t=62524

Look for the posts by DerekW #14

This is what I did and no CEL since

 

awesome!

you rock man.

btw, this wasnt a question of me being lazy and not doing a search for it... i had no idea what i would be searching for!

thanks for pointing me in the right direction!!

 

Yea. Who would think to search for cat CEL problems by typing "spark plug anti foul" .

I can't remember how I stumbled over it; just remember that when I threw that code I read about everything
that had "cat" and "cel" in it.

 

aight cool...lol i didnt know if you were being sarcastic at first.

i dont think you were.

 

I am pretty sure there are many fixes out there for this, o2 simulator, reflash, sensor positioning, etc. But they won't change the fact that the car probably won't pass emissions. They prevent the CEL from going on, but they don't change the underlying problem of the excessive emissions.

 

lolol underlying problem.


i think my car wasnt going to pass inspection when i tinted the windows a year ago....

 

I did the same CEL fix, no problems yet with the anti-fouler