P0303
Cylinder 3 Misfire Detected
Generic code
Ignition System
High severity
Hard repair
Free on OBD DashX
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What P0303 means
- The fault code P0303 indicates that the Engine Control Module (ECM) detected a misfire in cylinder 3. This misfire can cause damage to the engine and lead to reduced performance.
Possible symptoms
- Engine misfires or runs erratically
- Illuminated check engine light
- Reduced engine power or acceleration
- Rough idle or stalling
Possible causes
- Faulty spark plug in cylinder 3
- Bad ignition coil in cylinder 3
- Clogged or dirty fuel injector in cylinder 3
- Low compression in cylinder 3
- Vacuum leak in cylinder 3
- Faulty Engine Control Module (ECM)
Related parts
- Crankshaft Position Sensor: The crankshaft position sensor monitors the position of the crankshaft to regulate fuel injection. Problems lead to engine misfire and engine stalling
Possible solutions
- Replace spark plug in cylinder 3
- Replace ignition coil in cylinder 3
- Clean or replace fuel injector in cylinder 3
- Check and repair any issues with compression in cylinder 3
- Check for and repair any vacuum leaks in cylinder 3
- Replace the Engine Control Module (ECM) if necessary
Free on OBD DashX
P0303 on OBD DashX
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