'98 XJ Random missing/backfire

[CJ-3XJ]

I bought my '98 XJ Mar 2019. Replaced fuel pump, sparkplugs and wiring, replaced crank sensor, o2 sensors, added injector cleaner with each tank of gas. It runs quiet and smooth for 2-3 weeks at a time then will miss/stumble/backfire at various speed. Then it clears up for another 2-3 weeks and repeat. Any ideas what is the cause? Runs great in between.

[4.3LXJ]

What brand O2 sensor did you use when you replaced it?

[CJ-3XJ]

Will have to locate paperwork, I know they were purchased from ebay dealer.

[4.3LXJ]

The trick is to keep with Chrysler sensors on these 4.0L engines.