Air leaks at the exhaust manifold or in the exhaust pipes.Catalytic converter is damaged or has failed.Front HO2S or rear HO2S is contaminated with fuel or moisture.Front HO2S or rear HO2S heater is damaged or has failed.Front HO2S or rear HO2S is contaminated with fuel or moisture.
Answers & Comments
Trouble Code: P0422
Catalyst Efficiency Below Normal (Bank 1)
Possible Causes:
Air leaks at the exhaust manifold or in the exhaust pipes.Catalytic converter is damaged or has failed.Front HO2S or rear HO2S is contaminated with fuel or moisture.Front HO2S or rear HO2S heater is damaged or has failed.Front HO2S or rear HO2S is contaminated with fuel or moisture.