Im having very poor gas mileage. I have PCMForLess tuning, headers, Bosch O2 sensors installed in fall of 01, opti installed in 01, new plugs and wires. Im not sure if the PCM tuning is for power programming or not, but my car seems to be running very rich. The mileage is about 11 in the city with semi-hard driving. Ive been using medium octane gas with no difference in mileage. All I can think of is the O2s may be bad, but they shouldnt have gone bad so quickly. I know the O2 sensor wires have been fooled with...they have only 3 wires instead of 4, or 2 instead of 3 or whatever...one of them is cut and just laying there. I talked to a shop who said that setup would work. I failed the emissions test today and have 15 days to retest. Help....

 

Sounds like you're running really rich. I would check the O2's and the Cat.

 

the cats i hope arent a problem. ill definently change the O2s like tomorrow though. i think they sell those at AutoZone. hey i noticed you want a cutout. I have two QTEC cutouts i never installed if you are interested. $100 a piece with switch

 

Hey thanks But i've already got the DMH, just waiting to install it. Thanks for the kickass offer though, and I good luck with your O2's.

 

i might install them at some point because the open headers sound kick *** but you really cant do that around my house in the city. im going to maybe sell them and get GMMG exhaust after i sell my trombone

 

Thats cool. Cutouts sound badass when they're open.

 

Your 93 left the factory with single-wire O2 sensors. Did you convert them to 3-wire heated sensors? Whatever you've done it sounds screwed up, if you have cut off wires. Could be contributing to the problem.

Exhaust leaks and misfires will cause a "false lean" and cause the engine to run excessively rich. Have you checked for exhaust leaks or misses?