Fluctuating Idle 93 Sable

[kimchiman]

My 93 Sable, with a 3.0 engine, is experiencing idle problems and I don't know where to start in eliminating this problem. The car will idle smooth once under a load put sitting in park it will almost die and then rev back up. I also notice that when I'm driving on the highway and I start to slow down, the shifting back into first gear will cause the car again to fluctuate. This causes the car to jerk back and forth for a while until it levels out again once the car is almost stopped.

The car has had new plugs and wires, but that's about it. I've been told to look for vacuum leaks, but I can't seem to find any and also that it could be the idle air control valve. Do you have any suggestions. Things that I have noticed are: Poor fuel mileage (15 mpg) and the gas tank releases a lot of air when I remove the gas cap.

I'd appreciate any ones advice.

[scottgoood]

you need to have a diagostic scan run. It will quickly isolate the problem. It sounds like your oxygen sensor could be bad, but several other things can produce basically the same symtoms. Save yourself from tearing your hair out and hsve a diagnostic check run.