P1279
Air Fuel Ratio Sensor 1 Bank 1 Circuit Slow Response
Severity
⚠️ MediumCan you drive?
Yes, but get it checked soon
Approx. repair cost
$33–89 (est.)
Symptoms
- Increased fuel consumption
- Unstable engine idling
- Reduced engine power
- Check Engine light comes on
- Increased emissions of harmful substances
Causes
- Air-fuel ratio sensor malfunction
- Damaged or corroded wiring
- Bad contacts in connectors
- Problems with power or grounding of the sensor
- Malfunction of the engine control unit (rare)
How to Fix
- Check the condition of the sensor and its connectors
- Check the integrity of wiring and contacts
- Check the supply voltage and grounding of the sensor
- Replace the air-fuel ratio sensor if necessary
- Check and, if necessary, update the ECU software