Diagnostic trouble code P0303 — what it means, the common
causes, and how to confirm the real fault before replacing parts.
What does P0303 mean?
P0303 indicates: Cylinder 3 Misfire Detected.
This relates to the Ignition / fuel / Combustion - cylinder 3 system.
Common causes of P0303
Coil/plug cyl 3
Injector cyl 3
Low compression cyl 3
Wiring to cyl 3 coil
Get the confirmed root cause for P0303 — on YOUR vehicle
A code is a symptom, not a diagnosis. AutoDX Pro cross-checks several
independent assessments, pinpoints the actual root cause, gives you the
exact tests to confirm it, and shows the parts — only after the cause is
confirmed. Reads your scan-tool photo and decodes your VIN with open
recalls.
P0303 is a diagnostic trouble code: Cylinder 3 Misfire Detected.
What are the common causes of P0303?
Common causes include: Coil/plug cyl 3, Injector cyl 3, Low compression cyl 3, Wiring to cyl 3 coil. The exact cause depends on the vehicle — confirm it before replacing parts.
Can I keep driving with P0303?
It depends on the fault and your symptoms. Some causes are minor, others can damage components or affect safety. Get the root cause confirmed before deciding.
How do I fix P0303?
Confirm the actual root cause with targeted tests first, then replace only the part that's at fault. AutoDX Pro gives you the root cause, the exact tests, and the parts for P0303 on your specific vehicle.