so my '01 S w/ 95k miles just got a full Maxspeed Motorsports exhaust installed, with the 4 200 cell cats.
after i picked up the car it ran fine for the drive to work, but would barely idle when i got in the parking lot. idle swinging up and down +- 300 RPM, sounds very loud, exhaust tips black with soot.
drove it back to the shop and CEL came on. got to the shop and they checked the faults, and came up with Fuel Trim Adaptation faults.
so basically the engine can't adapt the fuel trims and it's running FULL rich (black tips).
they've tried moving the post-cat O2's around (exhaust has 4 O2 bungs on each side), but this should be front O2 related. i replaced the front O2 sensors with aftermarket ones about a year ago, so the shop is going to try factory O2s (another $500
) on monday.
if anyone has any ideas... ?