Circuit Description

Under normal operating conditions, HO2S1 produces a voltage that varies between 0.1 and 0.9 volt. PCM monitors this voltage and determines if exhaust system is lean or rich. During closed loop operation, PCM will compensate for a lean or rich condition by changing injector pulse width as necessary. DTC P0134 will set when:

• HO2S1 voltage remains at 300 mV or less for 10 seconds.
• HO2S1 voltage remains at 600 mV or more for 10 seconds.