P0175 System Too Rich Bank 2

P0175 means the control module reports a rich condition on bank 2. Bank comparison is important because the cause may be bank-specific or shared across the engine.

Code details

Generic OBD-II · P0

System: Fuel / Air
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace both upstream sensors automatically; trim comparison and fuel-pressure checks usually give a better direction.

Symptoms of P0175

Black smoke or a strong fuel smell from the exhaust.
Rough idle and poor fuel economy.
Hesitation or fouled spark plugs.
Check-engine light with strongly negative fuel trims.

Common causes of P0175

Leaking or dripping injectors, or high fuel pressure.
A contaminated MAF or a failing oxygen sensor.
A restricted air filter or intake.
A leaking fuel-pressure regulator drawing fuel into the intake.

Useful checks before replacing parts

Compare bank 1 and bank 2 fuel trims, upstream sensor activity, and freeze-frame conditions.
Check bank 2 injector leakage, fuel pressure, purge flow, intake restriction, MAF data, and exhaust sensor plausibility.
Look for companion misfire, airflow, coolant-temperature, or purge codes that can explain why the mixture is rich.

Related OBD-II codes

These nearby fuel / air entries can help compare wording and pin down the fault area.