P1273
Air Fuel Ratio Sensor 1 Bank 1 Lean Shift Monitoring
Severity
⚠️ MediumCan you drive?
Yes, but get it checked soon
Approx. repair cost
$33–89 (est.)
Symptoms
- Check Engine light comes on
- Reduced engine power
- Increased fuel consumption
- Unstable engine idling
- Possible misfires
Causes
- Air-fuel ratio sensor malfunction
- Engine vacuum leak
- Dirty or faulty fuel injectors
- Problems with the fuel pump or fuel pressure regulator
- Air filter clogged
How to Fix
- Check the air-fuel ratio sensor for damage.
- Look for vacuum leaks in the engine
- Check the condition of the fuel injectors
- Check the fuel pressure in the system
- Replace the air filter if necessary