P2180
System Too Rich Off Idle Bank 2
Fuel & air metering
Generic OBD-II
Medium
What it means
P2180 means the ECM's fuel trims show the air-fuel mixture on bank 2 running too rich (too much fuel) during off-idle, part-throttle driving. The engine still runs, but it's burning excess fuel — hurting economy, fouling plugs, and, if left unchecked, loading the catalytic converter with unburned fuel.
Medium
Can I keep driving? Drivable, but a rich mixture wastes fuel, can foul spark plugs, and over time harms the catalytic converter — address it before those add up.
Common symptoms
What you'll notice
- Check-engine light on (may enter reduced-power fail-safe)
- Rough running or hesitation off idle
- Poor fuel economy
- Fuel smell or, in bad cases, black exhaust smoke
Common causes
Most likely first
- Leaking or stuck-open fuel injector on bank 2Likely
- Excessive fuel pressure (faulty regulator)Common
- MAF sensor over-reading airflowCommon
- Faulty coolant temp sensor keeping the mixture in a rich warm-up modeLess often
- Faulty upstream oxygen sensor on bank 2Less often
- Leaking EVAP purge valve adding fuel vaporLess often
How to diagnose & fix
Work through it in order
- Read fuel-trim data — heavily negative trim on bank 2 confirms a rich condition.
- Check fuel pressure against spec; a high reading points to the regulator.
- Inspect for leaking or stuck-open injectors on bank 2.
- Check the MAF and coolant temp sensor readings for plausibility.
- Inspect the EVAP purge valve for leaking or sticking.
- Repair the confirmed cause, clear, and re-run a drive cycle.
FAQ
Quick answers
Is it safe to drive with P2180?+
Short-term yes, but a persistently rich mixture fouls plugs and can overheat and damage the catalytic converter, so don't leave it for long.
Can I just clear P2180?+
It returns within a drive cycle or two while the mixture is still rich; the underlying fuel-trim fault has to be fixed.
Related codes
Often seen with P2180
Read & clear P2180 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