P2187: System too lean at idle (Bank 1)
Drive carefully. Get it checked within a week or two.
Can I drive with P2187?
Yes, but drive carefully and get it checked soon. Air leak enters at idle, causing rough idle and stumbling when stopped.
What does P2187 mean?
P2187 stands for System Too Lean at Idle (Bank 1).
Symptoms you may notice
- Rough or vibrating idle when stopped in gear
- Hesitation or mild sputtering during initial acceleration
- Whistling or hissing noise from an intake vacuum leak
How much does it cost to fix?
Repair costs for code P2187 depend on the specific underlying root cause, ranging from simple DIY checks to component replacement. The table below lists the most common causes and rough price ranges in USD:
- Failed PCV valve / oil separator diaphragm
- Leaking intake manifold gasket
- Stuck open EVAP purge valve
- Dirty MAF sensor at low airflow
What to do next
- Check the PCV valve or valve cover breather for whistling or strong vacuum pull.
- Smoke test the intake system for idle vacuum leaks.
- Clean the MAF sensor wire with electronics cleaner.
Last updated: October 2026
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General guidance only, not a professional diagnosis. If the check-engine light is flashing, or the car is running rough, overheating or losing power, stop driving and get help.
About this code
Code P2187 is common on Audi, VW, Volvo, and Ford vehicles. It indicates the mixture is lean strictly at idle, but normalizes once you step on the gas. A torn PCV diaphragm on the valve cover is the culprit 80% of the time. The car can be driven safely, but idle will be rough.