Circuit Description

O2S1 produces a voltage that varies between 0.1-0.9 volt under normal operating conditions. PCM monitors this voltage and determines if exhaust is lean or rich. If voltage input at PCM is about 0.1 volt, exhaust is lean. If voltage input at PCM is about 0.9 volt, exhaust is rich. PCM constantly monitors O2S1 signal during closed loop operation and compensates for a lean or rich condition by adjusting injector pulse width as necessary. DTC P0130 will set when O2S1 maximum voltage average is more than 0.5 volt, or minimum voltage average is less than 0.04 volt with engine at idle and at normal operating temperature.