My roomate has BBK shorties, y-pipe, gutted cat, and open Borla on his 96 TA. We changed all the O2 sensors and such. We also took out the AIR system. I know you have to get the rear O2 sensor to think all is well. We have had the SES light on ever since we have been finished. Any trick on getting that to go out.

Also, is it normal for black smoke and a horrendous gas smell whenever you hit the gas? It does it even during normal acceleration. It hasn't been programed with the HPP III yet, will that fix it? He is also getting HORRENDOUS gas mileage. We were out for about 30 minutes last night. He was driving kind of heavy, but it wasn't anything really bad or out of the ordinary. I think he used a half a tank. What causes this? Any ideas?

One more thing, the other night we were out driving, and he gassed it. All of a sudden it sounded like it was missing. Th ecar bogged down real bad and it didn't accelerate worth a ****. Now it only happens when you are in high RPM's, or when you stomp on it and it has to down shift. Any ideas on this one?

Thanks fellas. PEACE!

What year car. Probably an EGR related code due to no back pressure reading on the wide open exhaust. Mileage should not go down after header install. Something amiss there do the usual check of air filter, tire pressure, fuel filter, injectors on that.

the only way to get the SES light to shut off is to either get O2 simms or to get them programmed out.

1996 TA. Has an abundance of mods.

I was curious if anything else he has would cause a problem. If you would, check the mods on his car from the sig below. Let me know if you have any ideas.

Thanks. Peace!

IF you didn't do O2 simms, that could be the code. Or deleting the AIR pump, since OBD-II knows when it isn't working. And you might have a burned wire (or wires), other misfires or leaks in the headers before the O2 sensors, all of which could cause a "false lean" condition, causing the PCM to add unneccesary fuel, causing black smoke, fuel smell in exhaust and poor fuel mileage. The excess fuel could also be causing an SES light, if its max'd out the long term fuel corrections. And as noted the EGR could also be the culprit with lower back pressure on the exhaust... I thinks that's at least 4 possible causes for the SES light.

You need to get a scanner on it, pull the codes, and check the long term fuel corrections and misfire records. Otherwise your just taking wild guesses.