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What should the O2 sensor voltage be?
approximately 0.45 volts
When the air/fuel ratio is perfect and the fuel mixture is 14.7:1 (stoichiometric), the sensor will generate approximately 0.45 volts. This is difficult for the engine controller to achieve. On a normal operating O2 sensor you should see the voltage bounce around quite a bit from rich to lean.
What should a post cat O2 sensor read?
Diagnosing air-fuel sensors The post-cat oxygen sensor paired with it should not oscillate, but instead stay pretty steady somewhere between 500 to 700 mV. Fundamentally, air-fuel sensors work just like regular oxygen sensors, but in a mirror fashion. When the condition is rich they decrease in voltage.
What are your OBDII O2 sensor voltage readings?
If an engine has suffered a recent head gasket failure, the O2 sensors may need to be replaced because of contamination. A good O2 sensor should show a lot of switching activity with readings bouncing back and forth from 0.3 volts or less to 0.8 to 0.9 volts . If the sensor is sluggish or reads low, it needs to be replaced.
What does O2 sensor do?
An O2 sensor is an electronic sensor designed to measure the oxygen level in the exhaust fumes that exit the engine after combustion. All combustion engines burn fuel by mixing it with oxygen, which is essential to run the engine.
Where is the O2 sensor located?
Oxygen sensors O2 sensors will always be located in the exhaust system. Their function is to sense how much oxygen remains in the exhaust that is flowing out of the engine, and report that information to the vehicle’s engine control computer.
What is a rear O2 sensor?
Rear Oxygen Sensor. A rear or downstream oxygen sensor is installed in the exhaust after the catalytic converter. It measures the amount of oxygen in the exhaust gases coming out of the catalytic converter. The signal from the rear oxygen sensor is used to monitor the efficiency of the catalytic converter.