SB21J001

An investigation of returned fuel injectors has shown that injectors are being unnecessarily replaced. We have identified a common occurrence of an illuminated Malfunction Indication Light (MIL) with DTC P0172 Fuel Trim System Rich set in the Engine Control Module (ECM). Through the analysis of returned injectors, we have determined the injectors were not the cause of this DTC setting. This DTC may be resolved by reprogramming the ECM with the revised calibration.