We are clueless. My son has a 2002 Z28. Wanted new headers, cats, and y-pipe for his graduation. Took the car to a respected place, but we're having all sorts of problems. Had Edelbrock headers put on; don't know about cats. Check engine light keeps coming on. Two air tubes weren't hooked up. Installer said we were supposed to take the computer out, send it off somewhere, and have the service code burned out. NO WAY would we ever do this. Car was still under new car warranty and we need to get emissions inspections. They connected the 2 air hoses and check engine light is on again. Now we're told the sensors are bad and need to be replaced. Someone told us the cats are much smaller than the originals and maybe they can't handle it. Any ideas? He wanted to take his car to college and we're running short of time. Thanks.

 

Have the PCM scanned to get the exact codes. That will tell you what the problem is. Otherwise you are just guessing, or at the mercy of your "installer", who sounds less than reliable. You can get an OBD-II code reader from Harbor Freight for $40. Some auto shops will scan it for free.... just make sure you get the EXACT numerical code from the scan.

It is possible to "program out" the various trouble codes, and do it in a way that will not result in a "system not ready" flag to be set, and picked up on an emissions check.

 

Do this first: Research speed shops or mechanics in your area who KNOW LS1 engines because all exhaust setups are not the same and this is not the same small block Chevy engine from the past that anyone can tinker with in their backyard. When you find one, go there, it's that simple. Trust me.


I had a good GM Master Tech. do all the stuff to my car you son had done to his and I would say it went 90% well. This was his first LS1 header and y-pipe install and he did pretty good, but wasn't familiar with things like how the O2 Sims worked, etc.

It sounds to me like everything on your son's car is in place correctly. I don't think you need to send the car's computer away because I didn't. You need to buy O2 Simulators and hook them up because they'll trick the car's computer into thinking the everything is fine and keep the SES light off.

Just get your son's car to someone who knows what they're doing, everything will be much easier.

 

If the AIR tubes weren't connected it's possible that triggered a code.

It sounds like they didn't finish their job to begin with. Stupid question, but the headers did come w/ AIR and EGR provisions, right?

To get the best of the gas mileage, I'd send the computer off to get it tuned for the LT's.. My gas mileage increased greatly after the tune. It'll also help your emissions too.. Your NOX readings may go up a tad from a slightly leaner mixture, tho.

And like stated above, find out what the code is for and go from there. I've never heard of anyone saying "have the code BURNED out." --

That exh shop doesn't sound like they know these engines that well.

I hope these responses help you and your son..