OK, I see now you are referring to the upstream 0/2 sensor. There are still 2 of those but they are pretty much the same. I know the plugs are very hard to reach on those. I usually use a long, thin screwdriver to release the locking tab and then pull on the wire. I use the same screwdriver to get it plugged back in later.
Sunday, September 7th, 2014 AT 5:37 AM