Intake Backfire

Ok folks I need some help. I have a 96 XJ 4.0 Automatic. I'm having issues whenever the jeep is under a load or on the interstate cruising at 70, it will start backfiring through the intake, you can stomp on it and power through but when you let off it keeps hesitating, but will go back to smooth idle. When I drive and don't push it, she runs like a dream, and idles perfectly. Has a new fuel pump, TPS, good CPS, cleaned IAC, cannot find a vacuum leak. Only code I get is for bad O2 sensor's which have been bad for a long time. So if you have any suggestions, I would greatly appreciate it.

Fix the O2 sensor problem. The backfiring is symptom of that, and not very likely a separate issue.

Will be changing both O2 sensors tomorrow.

Be sure to buy NGK/NTK sensors and not Bosch O2 sensors or generic auto parts store O2 sensors.