Saturn Vue P0303 Misfire on Cylinder 3: Causes and Diagnosis Guide
I recently replaced the spark plugs and ignition wires on my Saturn Vue, but the vehicle still shows a misfire on cylinder 3 (code P0303). I'm trying to determine whether the issue is caused by a vacuum leak, a faulty coil pack, or a defective fuel injector. Any advice on how to diagnose this effectively would be greatly appreciated.
Misfires on cylinder 3 can stem from multiple causes. If you don't have an OBD2 scanner, consider checking and eliminating potential issues systematically: swap the coil pack to another cylinder—this helps verify if the problem lies with the coil itself by observing whether the P0303 code persists or shifts. Similarly, test the fuel injector by swapping it with one from a different cylinder; if the misfire code changes or disappears, that points directly to the faulty injector. Always confirm the code update after each swap to validate your diagnosis.