Theory Of Operation

For an aged O2 Sensor, the response rate to the air/fuel change is slower than when it was new. The O2 Sensor tends to move less with the same air/fuel changes in a given time frame. Therefore by observing the activity of voltage readings from the upstream O2 Sensor, the quality of the O2 sensor can be detected. DTCs P113D and P113E are used to validate the high frequency switching of the O2 Sensor for DTCs P219A and P219B.