GMC Yukon: Warm Up Catalyst Efficiency → Below Threshold (Bank2)

P0431 is a standard OBDII trouble code, which means that it has the same meaning for the GMC Yukon as it would any other vehicle.  It is closely related to P0430 (which is one of the most popular OBDII codes). Warm Up Catalyst Efficiency → Below Threshold (Bank 2) When it’s the only trouble code … Read moreGMC Yukon: Warm Up Catalyst Efficiency → Below Threshold (Bank2)

GMC Yukon: Warm Up Catalyst Efficiency → Below Threshold (Bank 1)

P0421 is a generic OBDII trouble code.  It has the same meaning for the GMC Yukon as it would any other vehicle.  It is closely related to P0420 (which is the most popular OBD code). Warm Up Catalyst Efficiency → Below Threshold (Bank 1) When it’s the only trouble code present, P0421 will typically not … Read moreGMC Yukon: Warm Up Catalyst Efficiency → Below Threshold (Bank 1)

GMC Yukon P0411: Secondary Air Injection System → Incorrect Flow Detected

P0411 is a general OBDII trouble code, which means that it has the same meaning for the GMC Yukon as it would any other car or truck.  By definition, the code is letting you know that the ECM has detected incorrect flow in the secondary air injection system.  P0411: Secondary Air Injection System → Incorrect … Read moreGMC Yukon P0411: Secondary Air Injection System → Incorrect Flow Detected