P0278 Code: Cylinder 6 Fuel Injector Contribution/Balance
🟠 Moderate severity · drivable
Drivable, but the engine may run rough or shake at idle. Fix it soon to protect the catalytic converter.
What P0278 means
The computer compares how much power each cylinder makes at idle. Cylinder 6 is contributing too little or too much, which usually points to a fuel injector on that cylinder that is clogged, worn, or leaking.
Symptoms
- Check engine light on
- Rough idle or shaking
- Loss of power
- Poor fuel economy
Common causes
- most common: Clogged or faulty fuel injector on cylinder 6
- common: Injector wiring or connector problem on cylinder 6
- less common: Vacuum leak or air intake issue on that cylinder
- less common: Low compression in cylinder 6
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Run an injector balance test to confirm the problem | Mechanic | $50–150 |
| Clean or replace the cylinder 6 fuel injector | Mechanic | $100–300 |
| Check and repair injector wiring or connectors | Mechanic | $50–200 |
| Run a compression test on cylinder 6 | Mechanic | $100–200 |
Frequently asked questions
Can I drive with P0278?
Yes, but the engine may idle rough or shake. Fix it soon so the extra fuel doesn't damage the catalytic converter.
What does a contribution/balance code mean?
The computer found that cylinder 6 isn't adding the same amount of power as the other cylinders, usually because of a fuel injector problem.
What usually fixes P0278?
Replacing or cleaning the cylinder 6 fuel injector fixes most cases.
Related codes
P0276
P0276 Code: Cylinder 6 Injector Circuit Low
P0277P0277 Code: Cylinder 6 Fuel Injector Circuit High
P0306P0306 Code: Cylinder 6 Misfire Detected
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.