Conditions for Setting the DTC

WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

P0131 Lean Test

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.

P0131 Power Enrichment Test

The ECM detects that the HO2S 1 Voltage parameter is less than 800 mV.
DTC P0131 sets within 100 seconds during the power enrichment test when the above condition is met.

P0132 Rich Test

The ECM detects that the HO2S 1 parameter is more than 1,000 mV.
DTC P0132 sets within 15 seconds during the rich test when the above condition is met.

P0132 Decel Fuel Cut-Off Test

The ECM detects that the HO2S 1 parameter is more than 900 mV.
DTC P0132 sets within 10 seconds during the decel fuel cut-off test when the above condition is met.

P0137 Lean Test

The ECM detects that the HO2S 2 voltage parameter is less than 50 mV.
DTC P0137 sets within 100 seconds during the lean test when the above condition is met.

P0137 Power Enrichment Test

The ECM detects that the HO2S 2 voltage parameter is less than 550 mV and the HO2S 1 parameter is more than 800 mV.
DTC P0137 sets within 100 seconds during the power enrichment test when the above condition is met.

P0138 Rich Test

The ECM detects that the HO2S 2 voltage parameter is more than 1,000 mV.
DTC P0138 sets within 100 seconds during the rich test when the above condition is met.

P0138 Decel Fuel Cut-Off Test

The ECM detects that the HO2S 2 voltage parameter is more than 900 mV.
DTC P0138 sets within 100 seconds during the decel fuel cut-off test when the above condition is met.