P1284
Air Fuel Ratio Sensor 1 Rich Shift Monitoring Bank 2
Severity
⚠️ MediumCan you drive?
Limited driving only, diagnose soon
Approx. repair cost
$22–89 (est.)
Symptoms
- Increased fuel consumption
- Reduced engine power
- Black smoke from the exhaust pipe
- Unstable engine idling
- Gasoline smell from exhaust
Causes
- Air-fuel ratio (AFR) sensor malfunction
- Fuel leak in injectors
- Increased pressure in the fuel rail
- Contamination or malfunction of the air flow sensor
- Exhaust gas recirculation (EGR) system malfunction
How to Fix
- Check the operation of the bank 2 AFR sensor
- Diagnosis of fuel injectors for leaks
- Check the pressure in the fuel rail
- Clean or replace the mass air flow sensor if necessary
- Check the EGR system for correct operation