It's a 98 XJ.

I changed the fuse twice already and checked out the wires going to both sensors and the harnesses.

I can't find any burned or bare spots anywhere.

The rear sensor is only 2 years old, so I unplugged the upstream sensor and it runs well now but the CEL is on.

Thanks for any help.

 

If after unplugging the upstream oxygen sensor, the oxygen sensor fuse no longer blows....cause and effect tells us that you have found the root cause; replace that sensor. Consider replacing both of them at the same time

Be sure to use NTK sensors, the OEM brand for your 98. Widely available and quite affordable. There is no lack of total crap oxygen sensors on the market nowadays.

 

Thanks TJWalker.

I just now saw your reply when I was looking on here to see the best brand O2 sensor to buy.

You answered both my questions at once.