Well after my header install my car wont spin the tires anymore. Could this be due to the knock sensor pulling a lot of timing because of te louder exhaust? Oh And The exhaust seems to have some vibration at certain rpm's.

 

You need to get a Scanmaster or Datamaster to detect if the PCM is pulling timing, its possible.

 

I had 3 leaks from the connections. I had a muffler shop weld the new cat in but where the coated headers met he said he could not do it. I used the old aluminum foil trick and some clamps and got them i think. The noise under the car went way down. I already had the lt4 knock module so that was probably a big help. My 1/4 mile times dropped a lot after the leaks where fixed. My air pump valves where bad and i replaced them so that took a bad tick i was chasing and made it go away. I also waited a week and replaced the O2's. They can foul out from the gases from the coating until it burns off. I put my hands under the car after starting it cold and felt for air blowing from leaks. The worst thing is they heat up fast so beware.

 

Dude you have got to have the slowest S/C car ever!