October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.

Heated Gas Oxygen (HEGO) Sensor Test

Disconnect oxygen sensor connector. Measure voltage between oxygen sensor wire and ground. At idle voltage reading should be 0.2-0.8 volts. Increasing engine speed increases oxygen sensor voltage and decreasing engine speed decreases oxygen sensor voltage. Replace if out of specification.