Error code

OBD2 P2191

OBD2P2191
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

System Too Lean at Higher Load.

Severity

moderateCan drive but performance may be affected.

Summary

P2191 indicates that the engine is running too lean at higher loads in bank 1, meaning there's not enough fuel or too much air.

Symptoms

  • Poor engine performance
  • Misfiring
  • Poor fuel economy

Common Causes

  • Vacuum leaks from loose or broken vacuum hoses and intake gaskets
  • Contaminated mass airflow (MAF) sensor
  • Low fuel pressure due to fuel line issues

Diagnosis

  1. Check for vacuum leaks using a mechanic’s stethoscope or brake cleaner spray.
  2. Inspect the MAF sensor for contamination and clean if possible.
  3. Verify fuel pressure with a gauge during high-load conditions.

Fixes

  • Repair vacuum leaks, replace contaminated MAF sensor, address low fuel pressure issues

FAQ

What does P2191 mean?

P2191 indicates the engine is running too lean at higher loads in bank 1.

How do I fix a vacuum leak causing P2191?

Use a mechanic’s stethoscope or brake cleaner spray to locate and repair any loose or broken vacuum hoses and intake gaskets.

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