Drove it this week after changing the water pump, T-stat, hoses, harmonic balancer and timing chain. I have owned this Jeep since 2019, it is the 4th 4.0L Jeep I have owned, and driven/worked on many more. It has 167k on it, and always seemed a tad sluggish. Not bad, but noticeable. I've done all tune-up parts, PO installed 4 hole injectors, I replaced all the original throttle body sensors with Mopar. After the chain replacement, it seemed snappier, but still had a bit of a strange idle to it. I only noticed the chain was loose when I did the RMS/oil pan gasket two years ago.
I was flipping through the paperwork the previous owner gave me, and saw they replaced both O2 sensors with some store brand. I had only used NTK on my 4.0Ls as they are OEM, and replaced them today with some Mopar units (rebranded NTK Japan sensors), idle is perfect now.