P2189
System Too Lean at Idle Bank 2
Fuel & air metering
Generic OBD-II
Medium
What it means
P2189 means that at idle, bank 2 is running with too much air for the fuel supplied (a lean mixture) and the ECM has reached its correction limit. Because manifold vacuum is highest at idle, it's most often a vacuum or intake leak, though a dirty MAF sensor or low fuel delivery can also cause it.
Medium
Can I keep driving? Usually driveable, but a lean idle causes rough running and can lead to stalling or lean misfires, so address it before it worsens.
Common symptoms
What you'll notice
- Check-engine light on
- Rough or unstable idle
- Occasional stalling at idle or when coming to a stop
- Hesitation off idle
Common causes
Most likely first
- Vacuum or intake air leak on bank 2 (very common at idle when manifold vacuum is high)Likely
- Faulty or contaminated mass air flow (MAF) sensorCommon
- Incorrect or disconnected PCV hose routingCommon
- Low fuel pressure or restricted/dirty injectorsLess often
- Exhaust leak upstream of the O2 sensor, or a faulty front oxygen sensorLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame and fuel-trim data to confirm a lean condition at idle on bank 2.
- Smoke-test the intake and vacuum system — small leaks show up most at idle; check the PCV hose.
- Inspect and clean the MAF sensor and check the intake ducting for cracks or loose clamps.
- Check fuel pressure and injector delivery against spec.
- Inspect for exhaust leaks near the front O2 sensor; replace the O2 sensor only after leaks and metering are ruled out.
FAQ
Quick answers
Is it safe to drive with P2189?+
Short term, yes, but a lean idle can cause stalling and rough running. Fix it before it leads to lean misfires or leaves you stalled at a stop.
Can I just clear P2189?+
It comes back once the ECM relearns a lean trim at idle; the leak, metering, or fuel-supply issue must be repaired.
Related codes
Often seen with P2189
Read & clear P2189 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