OBD
P2351
Cylinder 9 Combustion Performance
What it means
P2351 means Cylinder 9 Combustion Performance.
Check these first
- A fouled spark plug or weak coil on cylinder 9
- A clogged cylinder 9 fuel injector
- Low compression in cylinder 9
- A vacuum leak feeding cylinder 9
What to do next
- Read misfire counters and cylinder 9 balance on a scan tool
- Inspect the cylinder 9 spark plug and coil
- Test the cylinder 9 fuel injector
- Perform a compression test on cylinder 9
- Repair the cylinder 9 fault found and recheck
- Clear the code and retest
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Updated
Generic SAE J2012 definition. Last updated 2026-10-10.