Some Chevy Malibu owners may notice that their vehicle has reduced engine power. Now, a possible cause for this issue has been identified, as has a possible fix to be performed by a GM technician.
According to a recent report from GM TechLink, some 2018 through 2022 Chevy Malibu vehicles may exhibit reduced engine power and one or more diagnostic trouble codes (DTCs) as the result of the Charge Air Cooler (CAC) outlet tube separating from the throttle body. Affected units are equipped with the turbocharged 1.5L I4 LFV gasoline engine, which is rated at 160 horsepower at 5,700 rpm and 184 pound-feet of torque. In addition to reduced engine power, affected units may throw one or more DTCs, including:
- P0101 (Mass Air Flow (MAF) Sensor Performance)
- P0172 (Fuel Trim System Rich)
- P0299 (Engine Underboost)
- P0506 (Idle Speed Low)
- P1101 (Intake Air Flow System Performance)
GM recommends that units of the Chevy Malibu which exhibit these conditions be checked by a GM technician. Technicians are instructed to inspect the CAC outlet tube connection at the throttle body. If the tube is disconnected, the CAC tube, tube retainer clip, and throttle body should be checked for damage as well. In certain scenarios, the CAC tube or throttle may be damaged and require replacement. GM notes that the throttle body and mass airflow sensor associated with the DTCs listed above do not need replacement unless they are damaged, or found to be the root cause of the DTC in question.
Damage to the throttle body may include aberrant witness marks around the outer lip of the throttle body, or around the central ridge. Abnormal marks or damage may indicate that the throttle body requires replacement. Additionally, if the GM technician finds that the CAC outlet tube is disconnected from the throttle body, the tube end should also be checked for contact damage or a missing O-ring seal. The tube assembly will need replacement if the tube is damaged, or the O-ring seal is missing.