Cylinder 3 Misfire Detected - Diagnosis Guide
Fix P0303 cylinder 3 misfire code. Learn the common causes and proven solutions for cylinder 3 misfiring.
Engine Problems
Symptoms
- 1Check engine light flashing or steady
- 2Rough running engine
- 3Power loss
- 4Increased emissions
- 5Hesitation during acceleration
Common Causes
- 1Bad spark plug
- 2Failed ignition coil
- 3Clogged fuel injector
- 4Vacuum leak
- 5Valve train issues
How to Fix
- 1Replace spark plug in cylinder 3
- 2Swap and test ignition coil
- 3Clean or replace fuel injector
- 4Check for vacuum leaks
- 5Test compression
What Does P0303 Mean?
P0303 indicates that cylinder 3 is misfiring. The ECM detects this by monitoring crankshaft position sensor signals for variations in rotational speed.Quick Test
Swap the ignition coil from cylinder 3 with another cylinder. If the misfire code changes to follow the coil, replacement is needed.Related Codes
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