I just changed the oxygen sensor on my series III yet the light remains on. I disconnected the negative battery terminal for over 30 minutes, and I drove a good 12 miles on the new sensor. the light is still on. What can I do, what could be wrong?

This morning right before I changed the o2 sensor I finished completely gutting and re-installing my catalytic converter, so it is essentially a straight pipe now. The o2 light was on well before I ever messed with the cat, so I don't know if that's pertinent.

Is there a second downstream o2 sensor I missed? Maybe a computer issue? Bad wire?

Your help as always is very appreciated.

 

AFAIK this oxygen sensor light is a "idiot light", ie it's not connected to the O2 sensor in any way. It was fitted to the US cars because the original o2 sensor lifetime was less than a certain amount (service interval?) so the light was installed to tell owners to go get the o2 sensor changed.

The light is driven from a counter. The counter is in the boot/trunk behind the rear panel. The rear panel is held in place by 2 of those big plastic screw things that release when you turn them half a turn.

The counter will look like a little black box. There is a button on it. I think you press and hold the button to reset the light. Not sure if you need ignition on or not. Fiddle and see

 

I knew I learned it from Doug.....

https://www.jaguarforums.com/forum/x...t-light-60327/

 

ah ha! wonderful ! I will get on it when I get back home =) I will update later. I always thought that light looked out of place, makes sense now. my 2000 Volvo s40 has an annoying service engine light like that that comes on every 3000 miles.

 

well that was like the easiest fix EVER! and the answer is NO, you do not need ignition. I just popped the panel pressed the button down all the way with the tip of a pen and that was that. when I started the car... NO oxygen sensor light. haha wished I had done that months ago! anyways, thanks again. =)