Severity: Moderate
Drivable, but it can cause more damage or poor economy. Get it checked within days.
What P2187 means
Lean at idle on bank 1, which typically means unmetered air getting in at idle.
Symptoms
- Rough idle
Common causes
Most likely first
- 1Vacuum leak
- 2PCV system leak
- 3Intake gasket leak
- 4Dirty MAF
How we diagnose it
- Smoke test
- Watch fuel trims at idle vs 2,500 rpm (trims improve with RPM on a vacuum leak)
Every vehicle sets codes under its own conditions. We check the factory diagnostic steps and service bulletins for your VIN, so the repair targets the actual cause.