P0175: Your engine is burning too much fuel on the passenger side
System Too Rich (Bank 2)
Yes, you can drive for now, but fix it soon. A persistently rich mixture damages the catalytic converter and fouls spark plugs. If you also have P0172, address both together.
What it means
P0175 means the Bank 2 side of the engine is running rich, and the computer has pulled fuel delivery back as far as it will go without fixing the problem. Bank 2 is the passenger side on most V-type engines. The fuel mixture is still too rich despite maximum negative fuel trim. When P0175 appears alone without P0172, the cause is more likely bank-specific, like a leaking injector or a Bank 2 upstream O2 sensor stuck rich. When both codes appear together, a shared cause like the MAF or fuel pressure is more likely.
Common causes
- Leaking fuel injector on a Bank 2 cylinderA dripping injector delivers uncontrolled fuel. Bank 2 specific codes often start here.
- Faulty MAF sensor (if P0172 is also present)A contaminated MAF reporting low airflow causes both banks to run rich simultaneously.
- Bank 2 upstream O2 sensor stuck leanA sensor falsely reporting lean exhaust causes the computer to keep adding fuel to a bank that does not need it.
- Excessive fuel pressureA faulty fuel pressure regulator or stuck-open check valve raises pressure on all injectors at once.
What it costs
- MAF sensor cleaning or replacement$50 to $300
- Fuel injector cleaning or replacement$150 to $600
- Bank 2 upstream O2 sensor$150 to $375 installed
- Fuel pressure regulator$100 to $300 installed
Symptoms
- Check engine light on, steady
- Drop in fuel economy
- Fuel smell in the exhaust
- Possible rough idle or black exhaust smoke
- Fouled plugs on Bank 2 cylinders
What to do next
Check whether P0172 is also set. If both codes are present, clean the MAF sensor first since it is a common cause and costs nothing if you have the spray. If P0175 is alone, look at Bank 2 specific components. Monitor live fuel trim data to confirm whether the trim is maxed negative at all conditions or only at specific RPMs.
Lewis reads both Bank 1 and Bank 2 fuel trim values live, so you can confirm whether the rich condition is Bank 2 only or affecting both sides equally. Download Lewis.
Related codes
FAQ
- How do I know which cylinders are on Bank 2?
- Bank 2 is the side without cylinder 1. On most GM and Chrysler V8s that is the passenger side. On many Fords it is also the passenger side, but it varies. Look up your specific engine.
- Can a stuck thermostat cause P0175?
- An open thermostat that keeps the engine running cold can cause a rich condition on both banks, not just Bank 2. You would typically also see a coolant temperature code.
- Does P0175 mean I need a new catalytic converter?
- Not necessarily. Fix the rich condition first. A converter damaged by rich running may need replacement after, but do not buy one before the fuel issue is resolved.