It turned out that my O2 sensors were OK - I tested them first by swapping locations. So my rear pre-cat is indeed bad. But its not plugged as far as I can tell, as I have full power and the engine runs fine. So it basically isn't operating to the efficiency its supposed to, which I don't care about. Especially after finding out that it costs $300 for a new one for the part alone, and the labor to replace it would be at least that much on top of it. Replacing it myself would be a horrific task since its nearly impossible to get at the exhaust manifold bolts. Also, headers cost $600 just for the parts.

So I decided to solve the check engine light by ordering a pair of MIL eliminators from Dallas Mustang, which will trick the computer into thinking the rear precat is fine, and will turn the CEL off.

I haven't had a chance to install them yet as I just got them, but I will this weekend.

'96 Contour SE, black / opal grey, MTX, every option, KKM intake, resonator removed, Flowmaster Series 40 DeltaFlow, GoodYear Eagle HP's, 115k miles, new paint 7/01. Driven cross-country 4 times.

'70 Corvette Stingray Coupe, Cortez Silver, 454 bored to 462, Muncie M21, too many mods to list, lots of fun. 335 rwhp / 365 rwtq

'02 Corvette Z06, Electron Blue / Black, every option. Stock for now...