Hello, I have a 1996 Ford Explorer 4.0 Liter. I have a check engine light on and I took it to Autozone to see why it was on. They scanned my computer and said that it was a O2 Sensor. They said it was bank 2 sensor 1. I bought a new sensor for it and put it in on the drivers side, close to the Transmition. And the check Engine light still come on. Took it back to autozone and they rescaned it and said it was still Bank 2, Sensor 1. We reset the computer and I have drove about 500 miles and it still stays lit up. What am I doing wrong? Do I have it in the right place? Please help

 

Mike,

From what you have written.....YES, it is in the right place. The fault codes make mention of both upstream and downstream sensors. My '97 has 2 on each pipe - yours may well have the same. If you can get the fault codes they are specific to top and bottom sensors. (there are 3 different fault codes for each upstream sensor!)
Keep at it!

Paul.

 

This is a good example of how computer code outputs aren't exactly perfect. I recall having the same code you have, on the same exact vehicle (1996 Ford Explorer 4.0). I also replaced the O2 sensor, but the code didn't go away. It would come and go, seemingly randomly. In passing, I read up on O2 sensors, and one book I read said that an O2 code can come up as a result of things like bad gas or engine mechanical problems. Got my fingers crossed, b/c the code's been gone for about 6 months now, and in the meantime, I replaced a leaky head gasket. So I'd say, check all your sensors and do a tune-up if you haven't already done so. That could be the problem!