LOCATION OF OXYGEN SENSOR

There's one in the exhaust pipe BEFORE the catylitic converter and one after. You want to replace the one BEFORE.

I have traced the drivers side- and I did find the one in the exhast just before it turns toward the passenger side to connect into the Y--- but there is a sensor,it seems a bit larger, in the drivers side manifold just before it connects into the exhast by the firewall???? What would that be??

That sounds like the one. Does it look like a big spark plug with a wire or

Although it seems strange that you found 2 on the drivers side that close to the engine. go to autozone.com and go to add vehicle or something like that, add your truck then look for the part and location.

This sensor is the on infront of the converter I believe. This W series exhaust has one infront of the cat and one behind. The one behind the cat is a littl efurther down and up high on top of the pipe. highly recommend replacing both of them if possible. You may be able to clean them with alcohol and dry with compressed air also. Good luck.

Andrew.