P0303 Fault Diagnosis: 2008 Chevrolet Silverado Engine Misfire
I'm experiencing a persistent P0303 diagnostic trouble code on my 2008 Chevrolet Silverado. The engine exhibits a noticeable stumble or misfire, particularly under load. To troubleshoot, I've already replaced the spark plug wires, spark plugs, and performed fuel injector swapping to isolate the issue. I also conducted a compression test to rule out mechanical problems. After each step, I cleared the code using an OBD2 scanner, only for P0303 to reappear consistently. Despite these efforts, the misfire persists. What other diagnostic steps should I consider to identify and resolve this P0303 issue?
Try swapping the coil pack with a cylinder on another bank and observe if the misfire code shifts to that cylinder. This test helps determine whether the issue is related to the ignition component or a more systemic problem like fuel delivery or engine timing.