P0266 Code: Cylinder 2 Not Contributing Enough Power (Contribution/Balance)
🟠 Moderate severity · drivable
Drivable short-term, but the engine may run rough and lose power. Fix it soon to avoid further damage.
What P0266 means
The engine computer runs a fuel balance test that compares how much power each cylinder makes. This code means cylinder 2 is contributing less power than the others, so it isn't firing as strongly as it should, usually because of a fuel or compression problem in that cylinder.
Symptoms
- Check engine light is on
- Rough idle or engine shake
- Misfire or hesitation under load
- Loss of power
- Poor fuel economy
Common causes
- most common: Clogged or faulty fuel injector on cylinder 2
- common: Low compression in cylinder 2 (worn rings, valves, or head gasket)
- common: Air or fuel supply problem affecting cylinder 2
- less common: Leaking or sticking injector
- rare: Worn engine internals such as a damaged cam lobe or lifter
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Run an injector balance test with a scan tool | Mechanic | $80–150 |
| Replace the cylinder 2 fuel injector | Mechanic | $150–600 |
| Perform a compression test on cylinder 2 | Mechanic | $100–200 |
| Repair air or fuel leaks affecting cylinder 2 | Yes | $10–100 |
Frequently asked questions
Can I drive with a P0266 code?
Yes for short trips, but the engine may run rough and lose power. Continuing to drive can worsen the problem and hurt the catalytic converter.
What does contribution/balance mean?
The computer measures how evenly each cylinder fires. P0266 means cylinder 2 isn't contributing its share of power compared to the other cylinders.
How much does it cost to fix a P0266?
Often $150–$600 if the injector is replaced. If it turns out to be low compression or an internal engine problem, repairs cost more.
Related codes
P0263
P0263 Code: Cylinder 1 Not Contributing Enough Power (Contribution/Balance)
P0269P0269 Code: Cylinder 3 Not Contributing Enough Power (Contribution/Balance)
P0302P0302 Code: Cylinder 2 Misfire Detected
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.