P0172Medium severity

System Too Rich Bank 1

The engine is running too rich on bank 1, meaning too much fuel or not enough air.

Safe to Drive?
Yes

Informational only. Consult a qualified mechanic.

Estimated Repair Cost
$100 - $500
Common Causes
  • Dirty air filter
  • Leaking fuel injector
  • Faulty O2 sensor
  • High fuel pressure
  • Faulty MAF sensor
Recommended Action

Replace air filter, check fuel injectors, and inspect O2 sensors.

What does P0172 mean?

The P0172 OBD-II diagnostic trouble code (DTC) indicates: system too rich bank 1. This is a medium-severity powertrain code that your vehicle's onboard diagnostics system triggers when the engine is running too rich on bank 1, meaning too much fuel or not enough air. If your check engine light is on with this code, the vehicle is generally safe to drive, but you should have it inspected soon.

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