P0291
Fix within a few daysThe engine's computer detected an electrical problem with the fuel injector for cylinder 11.
Code P0291 means your engine's computer detected an electrical problem with the fuel injector for cylinder 11. Common causes: Bad fuel injector (70%), wiring issue (25%). Drivability: No, stop driving if flashing CEL. Repair cost: $100-$300 DIY, $250-$600 professional.
Can I Drive With P0291?
No, stop driving
Immediate repair needed
Stop driving immediately if: Flashing Check Engine Light, loud engine noises, burning smell, significant power loss
Symptoms of P0291
- 1Check Engine Light is on or flashing
- 2Engine misfires or runs rough
- 3Reduced engine power
- 4Poor fuel economy
- 5Engine hesitation or stumbling
- 6Rough idle
Common Causes of P0291
Parts most likely causing this code, ranked by probability
The fuel injector itself has an internal electrical fault, preventing it from opening or closing correctly.
70% of P0291 cases are fixed by replacing this part
An open circuit, short circuit, or corroded connection in the wiring harness leading to the cylinder 11 fuel injector prevents proper electrical signal.
25% of P0291 cases are fixed by repairing wiring or connectors
The engine's computer has an internal fault and is not sending the correct electrical signal to the cylinder 11 fuel injector.
5% of P0291 cases are fixed by replacing the PCM/ECM
Check These First (Before Buying Parts)
- Visually inspect the wiring harness and connector for the cylinder 11 fuel injector for any signs of damage, fraying, or corrosion.
- Ensure the connector is fully seated and secure on the injector.
How to Diagnose P0291
- 1Visually inspect the wiring and connector for cylinder 11 fuel injector for damage or corrosion.
- 2Using a multimeter, check the resistance of the cylinder 11 fuel injector. Compare to specifications and other injectors.
- 3Use a noid light to check for a pulse signal at the cylinder 11 fuel injector connector while the engine is cranking.
- 4If the injector resistance is out of spec, replace the injector.
- 5If the injector resistance is good but there's no pulse, check wiring continuity back to the PCM/ECM.
- 6If all other tests pass, swap the cylinder 11 injector with an injector from a different cylinder to see if the code moves.
P0291 on Popular Vehicles
Ford F-Series
1999-2016Ford F-250, F-350, F-450, F-550 with the 6.8L V10 Triton engine are common to see P0291. The fuel injectors can fail electrically or become clogged, leading to this code. Cylinder 11 is typically on the passenger side, second from the firewall.
75% fixed by replacing the fuel injector
Ford E-Series
1999-2014Similar to the F-Series, E-Series vans with the 6.8L V10 engine frequently experience P0291 due to a faulty fuel injector. Access can be more challenging due to the engine's location under the doghouse.
70% fixed by replacing the fuel injector
Dodge Ram
1994-2003Some older Dodge Ram trucks with the 8.0L V10 engine can also set P0291. While less common than the Ford V10, injector failures or wiring issues are the primary culprits.
65% fixed by replacing the fuel injector
Frequently Asked Questions
What does P0291 mean?
P0291 indicates the engine's computer has detected an electrical fault in the circuit for the fuel injector on cylinder 11. This means the computer is not seeing the expected electrical resistance or signal from that injector.
Can I drive with P0291?
No, stop driving if the Check Engine Light is flashing. A flashing light indicates a severe misfire that is actively damaging your catalytic converter. If the light is solid, limit driving to essential, short trips and fix it within a few days to prevent further damage.
Will P0291 clear itself?
No, P0291 will not clear itself. This code points to a hard electrical fault with the injector or its wiring. The underlying issue must be repaired before the code will clear, either automatically after several drive cycles or by using an OBD-II scan tool.
How do I fix P0291 myself?
Start by visually inspecting the wiring and connector for the cylinder 11 fuel injector. If no obvious damage, test the injector's resistance with a multimeter. If it's faulty, replace the injector. If the injector is good, use a noid light to check for a pulse signal at the connector. If no pulse, trace the wiring back to the PCM for opens or shorts.
How much does it cost to fix P0291?
The cost to fix P0291 yourself is typically $100-$300 for a new fuel injector and basic tools. If you take it to a professional shop, expect to pay $250-$600, which includes parts and 1-3 hours of labor.
P0291 keeps coming back - why?
If P0291 keeps returning, it means the root cause was not fully addressed. Common reasons include a faulty replacement injector, an intermittent wiring issue that was missed, a problem with the injector driver circuit in the PCM, or a poor connection at the injector or PCM.
Will P0291 fail emissions/smog test?
Yes, P0291 will cause your vehicle to fail an emissions or smog test. The Check Engine Light being on is an automatic failure, and a misfire code like P0291 indicates an issue that directly impacts exhaust emissions.
What's the difference between P0291 and P0301?
P0291 specifically indicates an electrical circuit fault with the cylinder 11 fuel injector. P0301, on the other hand, means a general misfire has been detected in cylinder 1. While a P0291 will cause a P0301, P0301 can be caused by many other issues like a bad spark plug, ignition coil, or low compression, not just an injector circuit fault.
P0291 on Ford F-Series/E-Series V10?
On Ford F-Series and E-Series vehicles equipped with the 6.8L V10 Triton engine, P0291 often points to a failed fuel injector. These injectors can become clogged or develop internal electrical faults with age and mileage. Always confirm with electrical testing before replacing.
Questions to Ask Your Mechanic
Did you test the resistance of the cylinder 11 fuel injector and compare it to specifications?
Good answer: Yes, the injector resistance was X ohms, which is outside the factory spec of Y-Z ohms. We confirmed the fault internally.
What did you find when checking the electrical pulse at the injector connector?
Good answer: We used a noid light and confirmed there's no pulse, indicating an issue upstream in the wiring or PCM, not the injector itself.
Repair Cost Estimate
DIY Repair
Parts only
$100-$300
Shop Repair
Parts + labor
$250-$600
Save $150-$300 by doing it yourself
Difficulty
intermediate
Time
1-3 hours
Intermediate - requires electrical testing with a multimeter and noid light, and potentially working with the fuel system.
Cost of Waiting
Ignoring P0291 and the associated misfire will send unburned fuel into your exhaust system. This rapidly overheats and destroys your catalytic converter, turning a $100-$300 fuel injector job into a $800-$2,500 catalytic converter replacement.
While You're In There...
These seals are removed and often damaged during injector replacement. Replacing them prevents fuel leaks and vacuum leaks.
If the fuel rail needs to be removed for access, replacing its gaskets prevents vacuum or fuel leaks upon reassembly.
Tools You'll Need
- OBD-II Scan Tool
- Multimeter
- Noid Light Set
- Fuel Injector Removal Tool (if applicable)
- Socket Set
- Wrench Set
- Screwdriver Set
P0291 is a common electrical fault for a fuel injector. While it needs prompt attention, it's a very fixable issue. Most repairs are straightforward, and your engine will run smoothly once the faulty injector or wiring is addressed.
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Your Next Steps
Step 1: Visually inspect the wiring and connector for cylinder 11's fuel injector. Look for cuts, frays, or corrosion. Ensure the connector is fully seated.
Step 2: Use a multimeter to test the resistance of the cylinder 11 fuel injector. Compare its reading to the manufacturer's specifications and to other injectors on the engine. If it's out of spec, replace the injector.
Step 3: If the injector resistance is good, use a noid light to check for an electrical pulse at the injector connector while the engine is cranking. If there's no pulse, you'll need to trace the wiring back to the PCM for an open circuit or check the PCM itself.