P0291 — Cylinder 10 Contribution/Balance Fault
Drivable short-term, but fix now to avoid damage.
What P0291 means
This code means the engine computer found that cylinder 10 is contributing too little or too much power compared to the other cylinders, upsetting the engine's balance. It usually points to a clogged or weak fuel injector, low compression, a vacuum leak, or an ignition problem on that cylinder. Fixing it typically involves cleaning or replacing the injector and checking the cylinder's compression and spark.
Common symptoms
- Check engine light is on
- Rough idle or engine shaking
- Noticeable misfire under load
- Loss of power or poor acceleration
- Increased fuel consumption
Common causes
- Clogged or weak fuel injector on cylinder 10
- Low compression in cylinder 10
- Vacuum leak affecting that cylinder
- Faulty spark plug or ignition coil
- Wiring or connector problem at the injector
Typical repair cost
$150 – $700
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0291 code?
Short trips are usually fine, but don't let it linger. An imbalanced cylinder makes the engine run rough and can damage the catalytic converter over time, so get it checked soon.
How much does it cost to fix a P0291 code?
Repairs typically range from $150 to $700. Cleaning or replacing an injector is at the lower end, while compression-related or ignition repairs can push the cost higher.
Is P0291 a serious code?
Yes, it's fairly serious because a cylinder isn't working properly. The car may still drive, but the rough running and potential converter damage make prompt repair worthwhile.
Does P0291 always mean a bad injector?
Not always. It can also stem from low compression, a vacuum leak, or an ignition issue on cylinder 10, so a technician will usually run a compression and balance test to find the true cause.