Conditions for Setting the DTC

WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

P0131

The ECM detects that the HO2S 1 Voltage parameter is less than 50 mV.
DTC P0131 sets within 100 seconds during the lean test when the above condition is met.

P0132

The ECM detects that the HO2S 1 parameter is more than 1,050 mV.
DTC P0132 sets within 15 seconds during the rich test when the above condition is met.

P0137

The ECM detects that the HO2S 1 voltage parameter is less than 50 mV.
DTC P0137 sets within 100 seconds during the lean test when the above condition is met.

P0138

The ECM detects that the HO2S 1 voltage parameter is more than 1,050 mV.
DTC P0138 sets within 100 seconds during the rich test when the above condition is met.