1997 Pontiac Grand Am -- Check Engine Light

Maintenance/Repairs
1

I have a 1997 Pontiac Grand Am, 2.4L, 130K I recently purchased for my teenage son. The car looks and rides fine now. It had an engine miss at idle. It passed a CA Smog Check. However, I have issues with the CEL. My mechanic read the code and it was “P0302 – misfire on cylinder #2”. To address the issue he replaced all four spark plugs, removed the original fuel filter (!) replaced with new, and dumped a bottle of fuel injector cleaner in the gas tank. The car is not burning/leaking coolant, the coolant is not contaminated with oil, the oil is not contaminated with coolant, the engine temperature is in the normal range. My mechanic tells me just to keep driving it and not to worry about the light.



The mechanic got the light to go off, but it will come back on after a cold start. The engine miss is slightly noticeable just before it comes back on. The CEL went out for me after a long freeway trip and stayed off for while, but after a cold start it was back on again.



BTW, the car sat for about a month before I bought it.



Any ideas?

2

You need to go to one of the autoparts stores that pulls these CEL codes and post them back here. I think you have a diffrent problem but won’t know for sure untill you post the codes.

Make sure you get the code number and not just the description.

3

The mechanic did the right things. He should have changed the spark plugs wires, too. To solve a misfire, can be a time consuming process, requiring some expensive tools, and mental effort. Check the strength of the spark on #2. Compare it to another spark plug. If it’s weak, suspect the ignition coil. If you can swap the #2 ignition coil with another, do so, and retest. Use a noid test light on the #2 fuel injector. A noid is under $5 from your local auto parts store. During cranking, or engine running, is #2 noid flashing steadily? If not, you, or somebody, has some trouble-shooting to do. At this point, it might be time to put it into the repair shop.

4

Thanks for the info. I’ll look into buying some good spark plug wires and then push on to the other suggestions.

5

I’ll look into buying some good spark plug wires

Frankly the best spark plug wires are OEM (Original Equipment) The fancy expensive ones at the shop are at best no better and many will cause problems, the cheap stuff is just that. Go for the original make if possible.