My grand am began shaking (shuddering) consistently yesterday morning and I ran a diagnostic reading on the car. It told me that there was a misfire. I replaced the spark plugs and still no change. This car has been a nightmare to do maintenance work on since everything is either within a case or impossible to access on a regular car jack- so I wanted to know if anyone had any other ideas as to what could be causing this reaction in the car? Is it definitely the ignition coil? I would just hate to attempt to replace that (not to mention the fact that it’s $100+ for the part) if I didn’t survey other options. Any help or suggestions would be appreciated. Thanks.
A misfire doesn’t refer to spark, in particular. The PCM doesn’t actually know anything directly about spark.
There are 4 things that the engine needs to “fire”: fuel + air + compression + spark. A misfire can be caused by an issue with any one of these things.
Attention to spark plugs & wires is a typical first step, however.
What was/were the specific error code/s that you pulled? How old are those spark plug wires? Did you at least inspect the coil packs to look for obvious issues? (Corrosion, cracks, etc.)