Rough Idle 2000 grand am, 85,000. i've put a new fuel filter, had it checked and they said it was missing so i replaced plugs and wires, didn't help. then was told had a vacuum leak on fuel injector, so replaced o-rings, didn't help. cleaned sensors. nothing seems to help. if i put it in nuetral or park still idles rough but not as bad.

SOURCE: 1991 jeep cherokee running rough.

It could be the alarm. Lock the drivers door with the key and unlock it this will reset the alarm if thats the problem.

SOURCE: 1993 pontiac grand prix 3.1 liter

the 3.1 had some EGR problems, EGR valve stuck open, blown diaphrams, Plugged passages Im not saying that is all your problems and I believe yours has whats called a linear EGR about $350.00 from the dealer (and that is the only place you ever consider buying such a critical part for the emissions system regardless of the cost)
That car is so antiquated as far as computers go that relying on the codes is nearly pointless! Map code can set because of low engine vacuum which you will have with a poor running engine, Check for 5 volt reference voltage at the TPS and MAP with the key on and engine off if no 5 volt reference I suspect a Computer. Computer Ground is on the Thermostat housing and needs to be clean and secure.
There is a legit test in the GM factory manual called the TAP TEST take the ECM (computer) and slap it with an open hand, if the symptoms change the ECM is bad it's very common in the early-mid 90s for the computers to go bad in one way or another the circuit boards come loose and suffer also from cold solder joints.
Make sure the wires are on the correct plugs and hopefuly you used factory plugs and wires and No split fire or bosch plugs only AC delco
Make sure you have good spark on all 6 cylinders.
Contact me at [email protected] with the results and any feedback or questions

SOURCE: 2000 Grand Am rough idle

check vacuum hoses

SOURCE: 2001 Ford Windstar runs rough.

remove the coil pack and look at bottom of it if it shows any cracks coil is bad very common on these vans if you have a noid light check for injector pulse on #4 if you have pulse and good blue spark most likely the injector is bad you have to remove upper plenum to get injectors out let me know how you make out

SOURCE: We have a 2000 Pontiac Grand Am Se. The car

If this car uses an electrically heated O2 sensor, the heater portion may be bad. If the car has a lot of miles, the O2 sensor may be getting bad also.