Check the 'Possible Causes' listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
The cost to diagnose the P1138 GMC code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.
In order to control emissions, a catalytic converter converts any harmful exhaust emissions into harmless water vapor and carbon dioxide. The Powertrain Control Module (PCM) can monitor this process by using a rear Heated Oxygen Sensor 2 (HO2S 2). The HO2S 2, located in the exhaust stream past the catalytic converter, produces an output signal which indicates the storage capacity of the catalyst. This signal indicates the catalyst's ability to effectively convert the exhaust emissions. If the catalyst is functioning properly, the HO2S 2 signal will be far less active than the signal produced by the front Heated Oxygen Sensor 1 (HO2S 1).
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