P0266: Cylinder 2 Contribution/Balance Fault
Can you still drive? Yes, but engine roughness and vibration will be noticeable. Have the cylinder diagnosed to prevent secondary damage.
What Does P0266 Mean?
Code P0266 indicates that cylinder 2 is not contributing the expected amount of power during combustion. The ECM uses crankshaft position data to evaluate each cylinder's contribution and has determined that cylinder 2 is underperforming relative to the others.
Need to read your codes?
An OBD-II scanner lets you read and clear diagnostic trouble codes from your vehicle's computer. Most scanners work with any car made after 1996.
Browse OBD-II Scanners on AmazonCommon Causes
- Worn or clogged fuel injector on cylinder 2
- Low compression in cylinder 2
- Intake manifold leak near cylinder 2
- Faulty spark plug or ignition coil
Symptoms
- Check engine light on
- Rough idle
- Engine vibration at low RPM
- Reduced power
- Slight stumble on acceleration
Diagnostic Steps
- 1Perform compression test on cylinder 2 and compare to others
- 2Test fuel injector flow rate and spray pattern
- 3Inspect spark plug and ignition coil for cylinder 2
- 4Check for vacuum leaks at cylinder 2 intake runner
- 5Run a cylinder power balance test
Recommended Parts & Tools
compression tester
fuel injector
spark plug set
Estimated Repair Cost
| Type | Estimated Cost |
|---|---|
| Total Repair Cost Range | $100 - $1500 |
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Frequently Asked Questions
Is cylinder balance fault the same as a misfire?
Not exactly. A balance fault means the cylinder is producing less power than expected, which may or may not be severe enough to register as a full misfire.
Can a balance fault be caused by low compression?
Yes, worn piston rings, a damaged valve, or a blown head gasket can all reduce cylinder compression and cause a contribution fault.
Community Fix Reports
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