OBD
P051F
PCV Filter Restriction
What it means
P051F means PCV Filter Restriction.
Check these first
- A clogged PCV filter
- A kinked or blocked PCV hose
- A stuck PCV valve
- Sludge in the PCV system
What to do next
- Inspect the PCV filter and hoses for a blockage
- Check the PCV valve for sticking
- Replace the PCV filter
- Clean or replace the PCV hoses and valve
- Clear the code and retest
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Updated
Generic SAE J2012 definition. Last updated 2026-10-10.