I'd replace them both with 300,000 miles, thats crazy mileage.

 

Hi again

Thanks HeyYou, now I know for certain which O2 sensor to replace.

Hi Luke - I had briefly wondered if the wire was a supply to an aftermarket accessory, but the clip that holds the fuseholder is moulded-in to the lid of the black case next to the battery, and the wire appears to be part of the original wiring harness. It is even protected with the same black convoluted tubing.

I did learn today how to read the Fault Codes without a scanner, by cycling the ignition on then off 2 1/2 times without starting the engine and then reading the codes in the odometer window. I didn't know about that!

 

I agree, replace both, because the post cat sensor(the one you have a code for) will not have ANY effect on the stalling factor. Which is why it has been suggested to replace the pre cat o2.

 

Thanks zman17. I'll take the advice offered here and replace both sensors.

 

That red wire does look like a power cable for an aftermarket accessory. In my opinion looks like it would power an amplifier due to the in-line fuse. I just installed one in my truck which looks the exact same way.

 

Thanks for the advice on the mysterious red wire. I'll assume it's aftermarket and disconnect and insulate it off.

Is there a fuse associated with the Cruise Control? According to Section 12-13 in Haynes there is, it says to locate and check fuse, though I can find no fuse for it on the electrical diagrams in the same manual.

 

Download the FSM from the FAQ section. The diagrams should be more accurate for your year truck.