Code Definition

P2191 — System Too Lean at Higher Load Bank 1

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P2191

P2191 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P2191 is stored, the module has detected a signal or supply voltage higher than the expected operating range; and a bank-specific fault, meaning it applies only to one cylinder bank of a multi-bank engine.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P2191 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The Powertrain Control Module (PCM) monitors air to fuel ratio control using upstream oxygen sensor feedback during cruise and higher load operating conditions, adjusting injector pulse width through short term and long term fuel trim. DTC P2191 is set when the PCM reaches the maximum rich correction limit on Bank 1 fuel trim while attempting to compensate for a lean indication, and the measured mixture remains lean beyond the calibrated threshold under load. This indicates insufficient fuel delivery or excessive unmetered air entering the engine that the PCM can no longer compensate for. When...

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