P0266
Cylinder 2 Contribution/Balance Fault
Severeengine
Overview
The P0266 code indicates the engine control module has detected a cylinder 2 contribution/balance fault condition. This is an engine-related diagnostic trouble code that may indicate a mechanical or control issue affecting the engine's operation. Depending on the severity, this code may require immediate attention to prevent engine damage.
Symptoms
- Check Engine Light (MIL) illuminated
- Reduced engine performance
- Poor fuel economy
- Engine knocking or pinging
Common Causes
- Internal engine mechanical failure
- Worn engine bearings or internal components
- Low engine oil level or pressure
- Failed engine temperature sensor
Diagnosis Steps
- 1Connect an OBD-II scanner and read all stored trouble codes and freeze frame data
- 2Check engine oil level and condition; change if overdue
- 3Perform a compression and leak-down test
- 4Inspect related sensors and their wiring connections
- 5Listen for unusual engine noises indicating mechanical issues
Estimated Repair Cost
$200 — $3,000
Cost varies by vehicle, location, and repair shop. Includes parts and labor.
Commonly Affected Vehicles
Honda CivicToyota CorollaJeep WranglerNissan Maxima
Related Codes
More Engine Codes
Frequently Asked Questions
Engine codes can range from minor sensor issues to critical mechanical failures. If you notice overheating, knocking, or significant power loss, stop driving and have the vehicle towed to a mechanic.