Fuel and air metering
P0175 — System Too Rich (Bank 2)
The ECU is cutting fuel to correct bank 2 but the mixture still reads rich. There is too much fuel or too little air in the cylinders of the second bank.
Common causes
- Leaking or stuck-open injector on bank 2
- Fuel pressure regulator fault or high fuel pressure
- Dirty air filter or intake restriction
- Faulty MAF sensor reading too high
- Faulty bank 2 oxygen sensor
Symptoms
- Black smoke and fuel smell
- Poor fuel economy
- Rough idle
- Check engine light
How to check
- Compare fuel trims on both banks to see whether the fault is common or local
- Check the air filter and MAF
- Measure fuel pressure and check for leaking injectors
- Inspect the spark plugs on bank 2 and test the oxygen sensor
Can you keep driving?
Drivable for a short time, but the excess fuel can damage the catalytic converter. Have it checked soon.
Related codes
Frequently asked questions
- What does P0175 mean?
- Bank 2 has too much fuel or too little air, and the ECU cannot fully correct it.
- Is P0175 different from P0172?
- Only by bank: P0172 refers to bank 1 and P0175 to bank 2.
General reference information. It does not replace a diagnosis on your own vehicle. The same code can have different causes depending on make, model year and engine; check the manufacturer's documentation or ask a technician with a scan tool.