Error code

OBD2 P2187

OBD2P2187
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

System Too Lean at Idle.

Severity

moderateCan drive but may experience rough idling and stalling.

Summary

P2187 indicates a lean air-fuel mixture at idle on bank 1 of the engine.

Symptoms

  • Hard starting, especially when hot
  • Engine stalling frequently or unpredictably during idling
  • Rough, erratic, or fluctuating idle
  • Engine misfires during idling
  • Engine runs hotter than normal during idling
  • Stumbling or hesitation upon acceleration

Common Causes

  • Vacuum leaks in the engine vacuum system or EVAP systems
  • Leaks in the inlet manifold or other parts of the intake tract
  • Defective upstream oxygen sensor
  • Low fuel pressure due to issues with the fuel pump, filter, or regulator

Diagnosis

  1. Check for other codes and resolve them first.
  2. Inspect vacuum lines and repair any leaks.
  3. Clean or replace the MAF sensor if it is dirty or faulty.
  4. Test fuel pressure and check related components like the pump, filter, and regulator.

Fixes

  • Repair vacuum leaks in the engine vacuum system or EVAP systems.
  • Replace a defective upstream oxygen sensor if necessary.

FAQ

What does P2187 mean?

P2187 indicates an air-fuel mixture that is too lean (too much air, not enough fuel) at idle on bank 1 of the engine.

How do I fix a lean condition in my car?

Fixing P2187 involves addressing vacuum leaks or issues with the MAF sensor and ensuring proper fuel pressure.

View source

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.

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