Have a 1996 XJ6 vanden, won't pass emissions. I understand there are two 02 sensors. Should I replace both or which is more likely to be the troublesome one?

Thanks

david

 

You have 4 oxygen sensors. No single one is more or less likely to be faulty. A scan tool would normally be used identify a faulty sensor.

Is your check engine light on? Were you told that you have a faulty sensor?

Cheers
DD

 

wife took the car in for state inspection. Check engine light was not on. I havent seen the report. mechanic just told me over the phone it was an 02 sensor...

thanks for your help and advice. guess with 4 I shouldnt tackle it. dunno

 

will the readout from the state inspection tell me which sensor?

 

No, it will not. In fact, there will be no difinitive information that it is indeed a sensor causing the failure. That requires analysis of the data from an OBD scan. Not to say the mechanic is not correct, just that there are other causes for most any emmision test failure besides the lambda sensors.

Do you have access to an OBD scanner? I find it somewhat hard to believe the X-300 will fail a emissions test without a OBD fault code. It will be helpful to know what parameter it failed, and what the allowable and actual values were.