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P0172: System Too Rich (Bank 1)
Severity: Medium Drive gently and get it diagnosed soon.
What does P0172 mean?
The engine is getting too much fuel or too little air on bank 1, and the computer has pulled out as much fuel as it can.
Generic OBD-II definition: System Too Rich (Bank 1). Confirm applicability in your vehicle service information.
Common causes
- Leaking fuel injector
- Faulty MAF or coolant temperature sensor
- Excessive fuel pressure (bad regulator)
- Very dirty air filter
Symptoms
- Black smoke or fuel smell
- Poor fuel economy
- Rough idle
Can I keep driving with P0172?
Severity: Medium Drive gently and get it diagnosed soon.
If the check engine light is flashing or the car runs badly, stop driving and have it checked.
Typical fixes
- Check the air filter
- Test the MAF and coolant sensor readings
- Check fuel pressure and injectors