P1274
Air Fuel Ratio Sensor 1 Bank 1 Rich Shift Monitoring
Severity
⚠️ MediumCan you drive?
Limited driving only, diagnose soon
Approx. repair cost
$17–89 (est.)
Symptoms
- Increased fuel consumption
- Reduced engine power
- Black smoke from the exhaust pipe
- Unstable engine idling
- Smell of gasoline from the exhaust pipe
Causes
- Air-fuel ratio sensor malfunction
- Fuel leaking from injectors
- Increased pressure in the fuel rail
- Malfunction of the mass air flow sensor (MAF)
- Dirty or faulty oxygen sensor
How to Fix
- Check AFR sensor readings using a scanner
- Inspect fuel injectors for leaks
- Check the pressure in the fuel system
- Check the condition and readings of the mass air flow sensor
- Check the operation of the oxygen sensor