Hello. My 02 Saturn had a check eng light. Had it scaned and it said it needed a tuneup, miss fire in cyl #1 and a coolant thermo. Replaced thermo, flushed radiator and did a tuneup with new plugs and wires. Still miss fire in #1 when in idle but runs beautifully when driving and check eng light still on. Have switched wires, pulled plugs, checked arch, checked compression and running compression and it is all great. Tried changing the circut board but still the same and am going to try replacing the coils. The codes keep changing everytime we check them on scanner even coming up with numbers for things that are not even on this car.I have been searching online but no one posts back if any of the suggestions given have fixed the problem. Can u help.I need my car!
Sounds like a leaking intake manifold gasket really common on those cars when they built the engines they wrinkled the intake gaskets around the number 1 intake port causing vacuum leaks. Let it idle get some carb spray spray it around the number one intake tube which is over by the power steering pump. If the engine stumbles or dies its leaking. Let me know what you find.