Fault-Code Library · Combustion
P0303: Cylinder 3 misfire detected
The ECU detected repeated combustion misfires on cylinder 3.
Common symptoms
- •Engine shake
- •Poor acceleration
- •Flashing warning light
- •Rough cold start
Likely causes
- •Ignition component fault
- •Injector flow problem
- •Compression loss
- •Carbon buildup affecting airflow
First checks
- •Check cylinder-specific misfire data
- •Inspect plugs and coils
- •Confirm fuel and compression before replacing multiple parts
Important
A single-cylinder misfire that does not move with ignition parts needs deeper diagnosis.
A fault code identifies a detected condition, not a failed part. Confirm manufacturer-specific subcodes and live data.
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