i thought ive read about this here before, but i cant seem to find anything i need in a search. i have a 96 Z28, dual cats etc. if i switch to single cat headers, with air and egr, use a single cat, and O2 sims for the rear O2s, will i still be able to pass emissions?

in CT here now i believe they plug in something to the OBDII cars and it reads if you are throwing codes or not... would using O2 sims, or having them reprogrammed be recognized by the emissions check?

 

The sims make the computer think that the rear o2 sensors are there, so there won't be a code thrown. I doubt you'd have a problem.

Mike

 

just what i wanted to hear, thanks

 

Is there an easy way around OBDI emissons? That is all that is kind of holding me back.

 

Not exactly, the O2 sims only prevent the light from coming on, but on a scanner at a smog shop, O2 sims will set AT LEAST two "sensor not ready" lights. Check with injuneer, but O2 sims won't get you through a smog check.

 

Anyone know a way around a smog test? Like i said that is the only thing holding me back. I live in IL so its not the worst as far as emissions go but they are still strict enough to not let me get long tubes.

 

ah, thats exactly what i remembered reading the first time, any more specifics?

if this is true, it would seem anything but emissions legals shorties are my only choice. not only are they a bad design, they are so much more money than regular headers... unless i fab a dual cat y pipe.

thanks!

 

OBD1 is EASY to make pass even with a fairly wild combo, all you need is decent tuning and good cats for the emmisions part, any visual check could easily be harder to pass with a modded car.

On the original question, would it be so bad to just install both O2s behind the one cat? I mean if there is a cat there they should read good.

 

i never thought of that... i dont see why it wouldnt work?

 

Well what if you have an OBD I conversion in a 96 - 97 car will it still pass the computer scan or will the scan reveal the PCM switch?