System Too Rich (Bank 2)
Same condition as P0172 but on bank 2. When paired with P0172, suspect shared causes (fuel pressure, blocked air filter); when alone, suspect a bank-specific injector or oxygen sensor.
Affected components
- Fuel pressure regulator
- Fuel injector
- Oxygen sensor upstream
Common causes
- High likelihood: Fuel pressure regulator stuck closed
- Medium likelihood: Leaking fuel injector on bank 2
Possible symptoms
- Check engine light on
- Increased fuel consumption
- Black smoke from exhaust on acceleration
- Smell of unburned fuel, fouled spark plugs
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.