OBD
P0170
Fuel Trim Bank 1
What it means
P0170 means Fuel Trim Bank 1.
Check these first
- A vacuum leak on bank 1
- A dirty mass air flow sensor
- Weak fuel delivery
- A leaking fuel injector on bank 1
- An exhaust leak on bank 1
What to do next
- Read the bank 1 fuel trims
- Smoke test bank 1 for a vacuum leak
- Clean the mass air flow sensor
- Check the fuel pressure
- Test the bank 1 injectors
- Clear the code and retest
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Updated
Generic SAE J2012 definition. Last updated 2026-10-10.