So if you put on a test pipe and either use a anti fouler or disable the O2 won't the ECU been thrown off? How would this affect the overall performace and reliability of the engine? Correct me if I'm wrong but it the there is no O2 signal being sent how will the engine know how to correct for air temp, altitude or any other factors that come into play? I know that a re-flash will clear the CEL and disable it, but what if its 100 degrees the day you tune and winter rolls around?

 

its fine cuase u still have a pre-cat o2 sensor that is reading properly and will make any necessay adjustments that it wants to

 

To go a little more in depth the o2 sensor in the cat monitors emissions it DOES NOT have anything to do with the performance of the car. The o2 sensor by the turbo is what affects the cars performance and tuning.

 

I didn't know that, thats what I needed to know.

 

so since you made the mistake of doing us a favor, i'll bother you for another question then:


i kinda have the same problem only there is an additional kicker........i want to keep my car as stock as possible.......the only thing the previous owner did to it was a drop in filter and a 3in turbo back with a 'racing cat'......i don't know if that is 200 cell or 100 cell or what, but when i romp on it, i get a check engine light.....i had the dealership check it out and sure enough it's "cat not running at adequate efficiency".......


if i disable the CEL in software for "cat not running at adequate efficiency ", will the stealerships be likely to count that as an "ECU mod" and void my warrantee.....i know nobody can really predict what these fools do, but just curious if anybody had an idea....


i'd rather do a fix in software if i could as i think that would be ultimately more elegant, but i'd do it in hardware if that would be warrantee-safer.....

 

I have the o2 disabled in my car, and I actually took it to a referee station in CA to get my exhaust "sound checked" and "legally checked" because I got a fix it ticket. Sure enough, I didn't enable my rear o2, but I did install the o2 back into the stock cat.

Funny thing is, they plugged in their big tools and odb2 readers and did a pretty thorough visual check. And I passed with flying colors! So IMO I wouldn't worry about it voiding the warranty. If the state ref doesn't notice it....then i'm not sure if a mitsu tech would haha!

 

Thats a good question, I also will have to get my car emissoned in Dec so I'll have to put the stock cat and pipe on, so I was figuring using a mechanical CEL fix so that I can just put it back to "stock" for emissons. Does this sound right?

 

Why would u have to put the stock cat and pipe on?

 

I just figured to pass emissons you would have to have the stock cat back on, right?