P0175 - System Too Rich (Bank 2)
P0175 means Bank 2 fuel trim is correcting a rich condition. Prove whether extra fuel, incorrect airflow data, purge flow, or biased sensor feedback is responsible.
Code first. Confirm symptoms and checks before pricing parts.
Explore Related Systems
Compare nearby repair families.
Common Next Steps
Turn the code into the next check.
Check coil boots, carbon tracking, and whether the miss follows a swap.
Inspect gap, fouling, wear, oil, coolant, and plug-well condition.
Move to injector balance, pulse, or leak-down checks if the misfire stays.
Use compression or leak-down testing when spark and fuel checks do not move the fault.
Related Inspection
Code Overview
P0175 means Bank 2 fuel trim is correcting a rich condition. Prove whether extra fuel, incorrect airflow data, purge flow, or biased sensor feedback is responsible.
Common Causes
- Leaking injector, excessive fuel pressure, or restricted fuel return where applicable
- MAF over-reporting airflow or intake sensor data biased warm or cold
- Evap purge valve stuck open and pulling fuel vapor at idle
- Oxygen or air-fuel sensor feedback problem after fuel and airflow checks
- Engine coolant temperature data biased cold, causing added fuel
Symptoms
- Fuel smell
- Black smoke in severe cases
- Poor fuel economy
- Rough idle
- Fouled spark plugs
Diagnostic Steps
- Compare fuel trims, oxygen sensor activity, coolant temperature, MAF data, and purge command at hot idle
- Check fuel pressure and injector leak-down before replacing sensors
- Pinch or command purge closed where appropriate to see whether trims improve
- Inspect air filter, intake tract, and MAF sensor condition
- Verify repair with trims, tailpipe smell, idle quality, and readiness monitor behavior
Repair Difficulty
Moderate
General difficulty estimate for the most common repair path.
Related OBD Codes
Browse nearby codes when systems overlap.
Next Steps
Move from code to checks, then estimate.