P0175System Too Rich Bank 2
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- With closed-loop control the engine module corrects the injected fuel using the oxygen sensor: short-term fuel trim reacts within fractions of a second, long-term trim stores a learned base correction per load and speed range. Positive values mean fuel is being added because the mixture was lean, negative values mean fuel is being removed; around ±10 % is normal. P0175 is the bank 2 counterpart of P0172: long-term trim at its lower limit, mixture still rich. GM evaluates it like bank 1 with a passive test before the first purge and an active test with the purge valve closed; Ford at −25 % with purge off. Two trips, no limp mode. P0175 alone points to a bank-specific cause such as a leaking injector on bank 2; together with P0172 to fuel pressure, purge, ethanol learning on flex-fuel vehicles or fuel in the oil. GM and Ford bulletins document wrongly learned ethanol content and a purge valve stuck open as causes.
- What you may notice
- Check engine light on (after two drive cycles)
- Higher consumption, fuel smell
- Black smoke, sooted spark plugs
- Rough idle or starting problems after refuelling; converter damage possible later
- Likely causes
- LikelyPurge valve stuck open or charcoal canister saturated
- PossibleLeaking or dripping injectors on bank 2 (also direct injection)
- PossibleFuel pressure too high (faulty regulator, blocked return, regulator vacuum hose)
- PossibleFuel in the engine oil (short trips, leaking injectors), vapour via crankcase ventilation
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €40 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.