P2187 — System Too Lean at Idle (Bank 1)
Category: Powertrain Severity: Medium
Updated:
DTC code P2187 means: System Too Lean at Idle (Bank 1). It falls under the "Powertrain" category, with an estimated severity of Medium. Common causes include vacuum leak (hoses, intake gasket, PCV), broken PCV valve or diaphragm and dirty MAF sensor; it's worth confirming the diagnosis before replacing parts.
Possible causes
- Vacuum leak (hoses, intake gasket, PCV)
- Broken PCV valve or diaphragm
- Dirty MAF sensor
- Low fuel pressure
Symptoms
- Rough idle
- Hissing in the engine bay
- Check engine light
How to diagnose it step by step
- Listen for hissing at idle.
- Check the PCV valve.
- Do a smoke test.
- Clean the MAF.
- Measure fuel pressure.
How to fix it
P2187 is almost always a vacuum leak noticeable only at idle. On VW/Audi check the PCV valve diaphragm; in general, do a smoke test.
Estimated repair cost
Hose: $10–60. PCV valve: $40–200.
Frequently asked questions
What does DTC code P2187 mean?
System Too Lean at Idle (Bank 1).
Is code P2187 serious?
Severity Medium. Not urgent, but worth diagnosing to avoid bigger damage.
Can I keep driving with code P2187?
Yes, it is safe to drive.
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