P0291
Cylinder 11 Injector Circuit Low
Moderatefuel system
Overview
The P0291 code indicates a cylinder 11 injector circuit low condition has been detected by the vehicle's powertrain control module (PCM). This code relates to the fuel delivery and metering system, which is responsible for providing the correct amount of fuel to the engine. When this code is stored, the fuel system is not operating within the expected parameters, which can affect engine performance and fuel economy.
Symptoms
- Check Engine Light (MIL) illuminated
- Difficulty starting the engine
- Strong fuel odor from the engine bay
- Black smoke from exhaust
Common Causes
- Failed fuel pump or weak fuel pressure
- Damaged fuel lines or connections
- Faulty fuel pressure regulator
- Wiring issues in the fuel system circuit
Diagnosis Steps
- 1Connect an OBD-II scanner and read all stored trouble codes and freeze frame data
- 2Check fuel pressure using a fuel pressure gauge; compare to manufacturer specifications
- 3Inspect fuel lines, connections, and injectors for leaks or damage
- 4Test the fuel pressure regulator for proper operation
- 5Check the fuel pump relay and electrical connections
Estimated Repair Cost
$150 — $800
Cost varies by vehicle, location, and repair shop. Includes parts and labor.
Commonly Affected Vehicles
Toyota CamryHonda CivicHyundai SonataKia Optima
Related Codes
More Fuel System Codes
P0001Fuel Volume Regulator Control Circuit/Open
ModerateP0002Fuel Volume Regulator Control Circuit Range/Performance
ModerateP0003Fuel Volume Regulator Control Circuit Low
ModerateP0004Fuel Volume Regulator Control Circuit High
ModerateP0005Fuel Shutoff Valve "A" Control Circuit/Open
ModerateP0006Fuel Shutoff Valve "A" Control Circuit Low
ModerateFrequently Asked Questions
It depends on the severity. Minor sensor issues may allow short-distance driving, but fuel pressure or leak codes should be addressed immediately as they can cause stalling, engine damage, or fire hazards.