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P2191 is a diagnostic trouble code (DTC) for "System Too Lean at Higher Load Bank 1". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.
System Too Lean at Higher Load Bank 1
P2191 is an OBD-II generic code for the engine control module (ECM) detecting that the fuel control has reached its rich limits when the engine is under load on bank 1.
The engine control module (ECM) controls the fuel using a closed loop feedback system. If the system is trying to enrich the fuel mixture and the O2 sensor keeps saying the system is too lean on bank one, or if the system reaches 25% enrichment and the O2 sensor still indicates the system is lean, then the Check Engine Light is turned on and the code P2191 is set.
The fuel injection system on bank one is clogged causing the lean condition.
Scans for codes and documents the code in the ECM, then looks at the freeze frame data for failure
Monitors the O2 sensors for bank 1 while manually enriching the mixture with propane to see if the O2 sensor indicates rich
Removes all spark plugs on bank one of the engine and checks to see what plug is running lean
Follows the manufacturer pinpoint tests for diagnosis and replaces the clogged or defective injector for the lean running cylinder
Clearing ECM memory codes before checking the freeze frame data for the main failure problem, so the failure may be duplicated and repaired
Failing to clear the ECM codes after the codes are fixed so the ECM will enable the system to be normal again
Code P2191 is a code indicating the engine is running lean on only one side, and this lean condition can cause internal engine damage or cause the engine to misfire.
Code P2191 is for a lean running engine on bank one and the most common problem is the injectors getting clogged over time. As they clog over time, the engine will compensate by running the injectors rich to bring the system back to normal.
YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6220.