Dang O2 Sensor

Where the heck is the Bank 1 O2 sensor on a 98 XLT with V8? I get the PO131 code in the city, if I clear out the code and drive the highway, no problems....

Going by the P0131 code you are looking for the bank 1, sensor 1 O2 sensor. Bank 1 means it's located on the side with cylinder #1 (passenger side). And sensor 1 means it's the sensor before the catalytic convertor. So the sensor you're looking for is on the exhaust pipe coming from the passenger side before the y-pipe or catalytic convertor.

Thanks, I got that far too, but heck if I can find it on the pipe. Any idea of where that O2 sensor is?????

I have a 1998 XLT 5.0 also and was going to change that same O2 sensor since I was already changing the upstream driver's side sensor (which is much easier). The one you need to change is a total pain to get to unless you remove the center console inside the truck to get to the access opening underneath it on the transmission hump. The O2 sensor sticks right up on the top of the passenger side exhaust pipe so really doing it from underneath the Explorer ain't gonna happen. Even though you may be able to unscrew it from underneath you probably aren't going to be able to unplug it or plug it back in unless your arms are the size of one the Olsen twins' arms. Look for the thread regarding console removal and follow those directions and it shouldn't be too difficult to swap out, just a little time consuming. I ended up just doing the driver's side anyway since the it was the one throwing a code. Good luck.

Edit: Here is the link to remove the center console.
http://www.explorerforum.com/forums/showthread.php?t=209770

Thanks a ton, I think I should have think problem taken care of finally.....