P0175
System Too Rich Bank 2
Fuel & air metering
Generic OBD-II
High
What it means
P0175 means the engine on bank 2 (the cylinder bank without cylinder 1) is running with too much fuel relative to air, and the ECM has hit the limit of how far it can trim fuel back. It usually points to a false-high airflow reading, leaking injectors, or high fuel pressure. The car still drives, but the rich mixture hurts economy and can damage the catalytic converter over time.
High
Can I keep driving? Drivable, but a persistently rich mixture wastes fuel, can foul plugs, and over time can damage the catalytic converter — don't leave it unaddressed.
Common symptoms
What you'll notice
- Check-engine light on
- Poor fuel economy
- Strong fuel smell from the exhaust
- Rough running, and black smoke under load
Common causes
Most likely first
- Contaminated or skewed mass airflow (MAF) sensor over-reading airflowLikely
- Leaking or dripping fuel injectors on bank 2Common
- Excessive fuel pressure (failed regulator)Common
- Faulty upstream oxygen sensor on bank 2Less often
- Failed engine control module (rare)Less often
How to diagnose & fix
Work through it in order
- Read fuel-trim data — heavily negative long-term trim on bank 2 confirms the rich condition.
- Inspect and clean the MAF sensor and check for false airflow readings.
- Check fuel pressure against spec and inspect injectors for leaks.
- Test the bank 2 upstream O2 sensor's response and wiring.
- Repair the confirmed cause, then clear the code and recheck fuel trims.
FAQ
Quick answers
Is it safe to drive with P0175?+
Short term, yes, but running rich wastes fuel and can overheat and damage the catalytic converter, so repair it before long trips.
Can I just clear P0175?+
It'll come back — the ECM will re-detect the rich mixture on the next drive cycles until the underlying fault is fixed.
Related codes
Often seen with P0175
Read & clear P0175 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX