P0175: System running too rich (bank 2)

What P0175 means

The ECU has taken fuel away from bank 2 up to its limit and the oxygen sensor still sees a rich mixture. Bank 2 is the side of the engine opposite cylinder 1 and only exists on V or flat engines. If P0172 is also stored, look for a cause that affects both banks.

Most common causes

• Very dirty or blocked air filter
• Dirty or faulty mass air flow (MAF) sensor
• Leaking injector on bank 2 that does not close fully
• Fuel pressure too high because of the pressure regulator
• Coolant temperature sensor reporting a cold engine when it is warm
• Slow or failing bank 2 upstream oxygen sensor

Symptoms

• Engine warning light on
• High fuel consumption
• Smell of petrol from the exhaust or black smoke
• Rough idle

Can you drive with P0175?

With care You can drive, but fuel consumption goes up and the extra fuel can overheat and damage the catalytic converter. Get it checked soon.

How to check it

Compare the live long term fuel trim (LTFT) of both banks. If only bank 2 is strongly negative, suspect an injector or the oxygen sensor on that side; if both are, look at the MAF sensor, fuel pressure or the coolant temperature reading.

How to read and clear P0175 with Final OBD

Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P0175 with this same explanation and whether it’s confirmed, pending or permanent.

With Free you read this code with its short description for nothing, and clear it if the engine stores it over standard OBD. With Pro you get the full explanation, how the car was running when it was logged (revs, temperature, load) and clearing in every control unit.

Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before the ITV. It’s all in how to read and clear fault codes and in the ITV and OBD.

Similar codes

• P0171 Mixture too lean (bank 1)
• P0172 System running too rich (bank 1)
• P0173 Fuel trim malfunction (bank 2)
• P0174 System running too lean (bank 2)
• P0180 Fuel temperature sensor A circuit malfunction
• P0181 Fuel temperature sensor A range or performance problem
• P0182 Fuel temperature sensor A circuit low
• P0183 Fuel temperature sensor A circuit high
• P0100 Mass or volume air flow sensor circuit fault
• P0101 Air flow sensor range or performance problem
• P0102 Air flow sensor circuit low input
• P0103 Air flow sensor circuit high input

P0175 is a generic code, so it means the same on any make, for example on Alfa Romeo, Dacia, Kia, Nissan, Opel / Vauxhall, Škoda. See what Final OBD does on your car in makes and models.