OBD-II TROUBLE CODE GUIDE
P0172: System Too Rich — Bank 1
The engine computer is removing excessive fuel because the mixture appears rich.
What P0172 means
The engine computer is removing excessive fuel because the mixture appears rich.
Common possible causes
- Leaking injector or excessive fuel pressure
- Incorrect airflow reading
- Evaporative purge valve stuck open
What to check first
Record all stored and pending codes and freeze-frame data before clearing anything. Inspect relevant wiring, connectors, hoses, fluid levels, and obvious damage. Use vehicle-specific service information and test the affected system before purchasing parts.
A code is not a parts order. Several faults can create the same code, and replacing the component named in a code description may not correct the underlying problem.
Look up P0172 for my vehicle