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FuelSeverity Medium: diagnose soon

P2188System Too Rich at Idle (Bank 1)

What it means

The mixture on bank 1 is too rich at idle and the ECU has reached its correction limit.

Symptoms

  • Rough or hunting idle
  • Check engine light

Common causes

  • Leaking injectors
  • Fuel pressure too high
  • EVAP purge valve stuck open
  • MAF over-reading

What to check first

  1. Smoke-test the intake
  2. Compare fuel trims at idle and at 2,500 rpm
  3. Check the PCV system
Can I drive with P2188? Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.

Generic OBD-II meaning. Manufacturer-specific meanings and checks can differ; always check the service information for the car.

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P2188: questions and answers

What does P2188 mean?

P2188: System Too Rich at Idle (Bank 1). The mixture on bank 1 is too rich at idle and the ECU has reached its correction limit.

What are the symptoms of P2188?

Rough or hunting idle. Check engine light.

What causes P2188?

Leaking injectors. Fuel pressure too high. EVAP purge valve stuck open. MAF over-reading.

How do you diagnose P2188?

1. Smoke-test the intake 2. Compare fuel trims at idle and at 2,500 rpm 3. Check the PCV system

Can I drive with P2188?

Usually yes for a short distance, but performance or economy may suffer and the fault can get worse. Diagnose it soon.