P1156
HO2S Rich Average Bank 2 Sensor 1
Severity
⚠️ MediumCan you drive?
Yes, but get it checked soon
Approx. repair cost
$17–89 (est.)
Symptoms
- Increased fuel consumption
- Black smoke from the exhaust pipe
- Unstable engine idling
- Loss of engine power
- Smell of gasoline from the exhaust pipe
Causes
- Oxygen sensor (HO2S) malfunction
- Fuel leaking from injectors
- Increased pressure in the fuel rail
- Dirty or faulty MAF (mass air flow sensor)
- Problems with the EVAP system
How to Fix
- Check the condition and operation of the oxygen sensor bank 2, sensor 1
- Check injectors for leaks
- Check the fuel pressure in the rail
- Clean or replace the mass air flow sensor if necessary
- Check the EVAP system for leaks