What is a po303 code?

@cita17, Lorencita , P0303 PONTIAC - Cylinder 3 Misfire Detected

Possible causes:

Faulty spark plug cyl. 3/inspect change plug,clogged or faulty fuel injector cyl. 3, faulty ignition coil cyl. 3, fuel injector cyl. 3 harness is open or shorted, fuel injector cyl. 3 circuit poor electrical connection, Ignition coil cyl. 3 harness is open or shorted/poor connection, Insufficient compression(burnt/sticking valve cylinder cyl. 3, Incorrect fuel pressure/low,no fuel, Intake air leak/bad gasket/loose bolts,possible faulty O2 sensor, possible clogged catalytic converter. Link below gives more info. and the pic., shows #3 cylinder. You can probably check some of the things out yourself or take to a good local shop and have them diagnose and estimate repair. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.

https://www.autocodes.com/p0303_pontiac....