I had a 92...on that year the O2 sensor is almost meaningless. You could disconnect it and never throw a CEL It has a "timer" that I think monitors the odometer and at 125k it tells you to replace it or something like that , it has nothing to do with performance

 

What types of horror stories have you encountered on upgrading the radiator?
I use a 2 row all aluminum as my Goto upgrade. The thing I've experienced over the years is that you want an upgraded radiator that will still flex. Just looking at how the cherokee drives and how long the radiator is, we want that radiator to have some play. I would avoid 3 row all aluminums as they are just too thick and rip apart (I sell them, but only to the hardcore guys and gals that demand them) The 2 row all aluminum radiator for cherokee beefs the core up to 1 3/4 and is completely welded. It allows for that flex I mentioned and holds up.

I also usually just do a shroud and do 3 10 inch fans across for an electric fan system. I do a 185/170 wiring kit

link to the radiator and picture
https://www.radiatorexpress.com/product/221504


https://www.radiatorexpress.com/product/221944


Michael
Radiator Express

 

Closed loop has nothing to do with engine temp.
Mine changes from open to closed loop within a minute or so from cold start up and engine same temp. There's a few threads on that.


Unless you mean closed loop as in thermostat closed, which would be a confusing use of the term.