P0175 System too rich (bank 2)
What P0175 means
The engine computer has had to reduce fuel on bank 2 as far as it is allowed and the mixture is still too rich. Unburned fuel reaches the exhaust, which wastes fuel and can damage the catalytic converter. Bank 2 is the side of a V6, V8 or boxer engine that does not contain cylinder 1.
P0175 is a generic SAE J2012 code: it means the same on every make. The exact cause still depends on the car, so read the freeze-frame data before replacing parts.
At a glance
- Severity
- High
- Typical repair cost
- 50–600 €
- Workshop time
- 0.5–4 h
- Repair difficulty
- Medium
- DIY possible
- Yes
- Check engine light
- Yes
- Affects emissions test
- Yes
Parts and labour at an independent workshop in Europe. Main dealers charge more; the cause decides the bill, not the code.
Symptoms
- Check engine light on
- Higher fuel consumption
- Black smoke on acceleration
- Smell of unburned fuel
- Fouled spark plugs, possible misfires
Common causes
- Leaking fuel injectors on bank 2
- Fuel pressure too high from a faulty regulator
- Faulty mass air flow sensor over-reading airflow
- Faulty upstream oxygen sensor on bank 2
- EVAP purge valve stuck open
Can I keep driving with P0175?
Get it to a workshop within a few days. Running rich damages the catalytic converter over time.
What to check first
- Compare fuel trims on both banks: if both are rich (P0172 as well), look for a shared cause such as fuel pressure, the MAF or the purge valve.
- Test fuel pressure and check the purge valve is not stuck open.
- If only bank 2 is rich, check that bank's injectors for leaks and its upstream oxygen sensor.
- Check the coolant temperature sensor reading is correct.
Related codes
- P0174 System too lean (bank 2)
- P0173 Fuel trim malfunction (bank 2)
- P0172 System too rich (bank 1)
- P0171 System too lean (bank 1)
- P0170 Fuel trim malfunction (bank 1)
- P0181 Fuel temperature sensor A range/performance
- P0161 Oxygen sensor heater circuit (bank 2, sensor 2)
- P0160 Oxygen sensor circuit no activity detected (bank 2, sensor 2)
Data: TORKO fault-code catalogue, built on OBDex (CC0-1.0) and reviewed against workshop practice. Informational only — it does not replace a diagnosis by a mechanic.
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