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2004 AUDI S4
4.2L V8•AWD•AUTOMATIC•gas•BBK
1 active safety recall on this vehicle — view recalls
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Repairs0Labor497Torque3159Fluid10DTC956Battery1Maintenance0Recalls1
P1137moderate severityPowertrain

Long Term Fuel Trim System Too Lean Bank 2

on 2004 Audi S4 4.2L V8 · AWD

What this code means

The ECU detected that the long-term fuel trim for Bank 2 has reached the maximum lean correction limit. The fuel system cannot add enough fuel to compensate for the lean condition.

Symptoms

  • Check Engine Light
  • Rough idle
  • Lean misfire Bank 2
  • Hesitation
  • Reduced power

Common causes

  • Vacuum leak at Bank 2 intake
  • Clogged fuel injectors Bank 2
  • Low fuel pressure
  • Intake manifold runner flap issues
  • MAF sensor fault

Diagnostic steps

  1. Smoke test for vacuum leaks at Bank 2
  2. Compare fuel trims between banks
  3. Test fuel injector flow Bank 2
  4. Check fuel pressure
  5. Test MAF sensor output

Repair notes

Repair vacuum leaks or fuel delivery issues specific to Bank 2.

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