I have a CEL on and was told that its the O2 sensor and knock sensor. Well, knowing that the knock sensor doesn't trigger the light, it must be the O2. Anyways, I went to the mechanics today on another issue. He had my car raised and noticed that the ground wire for the O2 sensor was not connected to anything. Apparently, it was connected to a bracket that was holding the muffler assembly in place. Since that bracket rotted off, the O2 ground is just a peice of wire not connected to anything.

Do you think that this is the reason why the O2 set off the CEL? I don't want to bring it to a mechanic to tell me that and charge me $50 and also don't want to fail the Mass State Inspection and waste $30.

Any thoughts?

If I was to ground it, where do I ground it to if all the grounding points seem to be rusty?

Thanks Guys..

I have come on here before with issues and everyone has helped me out.
Thanks Again!

 

i would just replace with a new O2 and reset the ECU.

 

i would get a new o2 sensor but you can ground it to any part of the body