Universal (All Makes) Vehicle (OBD-II)
Severity:Common Causes
- map[cause:Failed wideband O2 sensor with an open internal trim circuit]
- map[cause:Open wire in the trim circuit between the sensor and ECM]
- map[cause:Corroded or damaged sensor connector pin]
- map[cause:Contaminated sensor from oil or coolant in the exhaust]
- map[cause:Age-related sensor degradation — wideband sensors wear over time]
How to Fix It
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Scan for all codes — look for fuel trim and other O2 sensor codes alongside P2626.
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Inspect the sensor wiring harness connector for damage or corrosion.
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Check for exhaust leaks near the sensor that could contaminate it.
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Test continuity of the trim circuit wires from sensor to ECM.
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Replace the wideband O2 sensor — internal trim circuit failures require full sensor replacement.
Frequently Asked Questions
What is a wideband O2 sensor?
A wideband sensor can measure oxygen levels across a much wider range than traditional sensors. They are used in modern vehicles for precise fuel control. They have more internal circuits, which means more potential failure points.
How much does a wideband O2 sensor cost?
Wideband sensors are more expensive than traditional ones. Expect to pay $80–$250 depending on the vehicle. OEM sensors are recommended for accurate fuel trim control.
Can I use a generic O2 sensor for P2626?
It's not recommended. Wideband sensors require precise calibration. Generic sensors may not be compatible and can cause additional fault codes.