I HAVE A 1998 FORD TAURUS GL 3.0 I WAS TOLD THAT IF MY CHECK ENGIN LIGHT WAS NOT LITE THIS COULD BE AN OXYGEN SENSOR PROBLEM AND I SHOULD CHANGE THEM. COULD NOT GET CAR INSPECTED DUE TO THIS PROBLEM
Do you have two lamps: one labeled 'check engine' and another 'maint reqd"? If so, the 'check engine' lamp is lighted only when a trouble code has been set. 'Engine maintence required' lamp is lighted for scheduled maintence items such as the oxygen sensor.
If you have only one lamp, then it has to do both duties described above. So if this lamp is dark, it implies no trouble has been detected or no maintence required. So, no light means no problem detected.
Maybe I did not understand the question. If you referring to the checkout routine the engine controller goes throguh when the key is first turned on and all the critical lamps are lighted momentarily as a check, if the 'check engine' lamp does not come on momentarily, this signals a problem in its circuit, and yes, the car can not be inspected. The problem could be something as simple as the lamp is burned out.
Bump-ing! Just another O2 sensor simple question.. How can I test it? I know that it can be tested in and out of the car.. But I dont really know how..
Here is a link that might be useful: Oxygen Sensor
Get a Chilton Repair Manual for your Car, go to an auto parts store they usually have them or can order one for you. I got one, and if you are somewhat Mechanically Inclined, you should be able to clean and/or replace it.