Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This means that the car's engine is not getting enough fuel when it's working hard, like when you're driving up a hill or accelerating quickly.
The engine control module (ECM) detects that the air-fuel mixture is too lean (not enough fuel) on Bank 1 during high load conditions.
P2191 indicates that the ECM has detected a lean condition in the air-fuel mixture on Bank 1 when the engine is under high load. This can be due to insufficient fuel delivery or excessive air entering the system.
• Check Engine Light on
• Poor acceleration
• Engine misfire
• Vacuum leak
• Faulty fuel pump
• Clogged fuel injectors
ECM: Engine Control Module
Lean: A condition where there is too much air and not enough fuel in the air-fuel mixture
• Check for vacuum leaks
• Inspect fuel pressure
• Examine fuel injectors for clogs
• Repair any vacuum leaks
• Replace faulty fuel pump
• Clean or replace clogged fuel injectors
• OBD-II scanner
• Fuel pressure gauge
• Vacuum gauge
$150 - $500
Moderate
• Ford F-150
• Toyota Camry
• Honda Accord
• Regular maintenance checks
• Use quality fuel
• Inspect fuel system components periodically
Engine Performance
• Avoid driving under heavy load until repaired
• Get a professional diagnosis if unsure
Check with manufacturer for powertrain warranty coverage.
This code has been commonly associated with fuel system issues in vehicles with higher mileage.
Moderate – Should be addressed soon to avoid potential engine damage.
Ignoring this code can lead to increased emissions and potential engine damage.
• Engine under high load
• Vehicle acceleration
Bank 1 refers to the side of the engine with cylinder 1, typically located on the driver's side in a V-engine layout.
Q: Can I drive with a P2191 code?
A: It's not recommended to drive for extended periods with this code, as it can lead to engine damage.
Q: What happens if I ignore this code?
A: Ignoring this code can result in poor engine performance and increased emissions.
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Fitment Required · Vehicle-fitment part
Commonly relevant for misfire, ignition-efficiency, and some drivability-related repairs.
Misfire and ignition-related faults commonly involve spark plugs as part of the repair path.
Check the correct plug type, gap, and engine application for your vehicle.
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Fitment Required · Vehicle-fitment part
Relevant when the fault points toward ignition-coil performance or cylinder-specific ignition issues.
Some ignition faults involve coil performance or cylinder-specific coil problems.
Match the coil to your engine and confirm the failed component before ordering.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.