smitty96lt4

New to the forum and just pick up a 96LT4 . I got in on the group purchase for the Corsa exhaust and now I have a question about long tube headers and passing emission testing in IL . Can I pass with long tube ? Maybe the Chicago Crew could help me with this.

VetteTech81

96-up have OBDII Testing so if you have a custom setup without cats you would need the PCM tuned to block the codes or O2 Sims. In otherwords, there not testing the actual emissions they are only checking with the pcm to see if there are not and emssions related codes set. Many people have passed by faking out the system this way.
-=Rick

smitty96lt4

Was thinking I would go with some Exotic Muscle long tube headers, Random Tech cats, and the Corsa cat-back could I get pass emission with this set up or would I still have to fake the O2 sensor . Hope I reply right it my first time

VetteTech81

Just depends how well the cats work and if the post cat 02's are installed. Basically what I was getting at is the only concern about the Long Tubes on a 96-up car in concerns to emssions is if the pcm is seeing a problem with cat efficieny.
-=Rick

smitty96lt4

Thank for the info . I"ll just have to install the system than have the pcm check for codes. I know very little about the computer side of these vette or any other cars. But I"willing to learn.

Gordy M

Find someone with HPTuners, EFILive or EASE scanning software and have them run the emissions test. It will tell you if you pass or fail. Several states are using the EASE software E/M for emission testing.

If you fail, then with HPTuners or EFILive, you can make the proper adjustments to pass the test.