OBD-II TROUBLE CODE GUIDE
P0303: Cylinder 3 Misfire Detected
Repeated combustion failures have been detected on cylinder 3.
What P0303 means
Repeated combustion failures have been detected on cylinder 3.
Common possible causes
- Spark plug or ignition coil
- Fuel injector
- Vacuum leak or low compression
What to check first
Record all stored and pending codes and freeze-frame data before clearing anything. Inspect relevant wiring, connectors, hoses, fluid levels, and obvious damage. Use vehicle-specific service information and test the affected system before purchasing parts.
A code is not a parts order. Several faults can create the same code, and replacing the component named in a code description may not correct the underlying problem.
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