2001 Jeep Cherokee - What is this noise?

very soft ticking noise with engine running

Could be an exhaust leak… will be impossible to say without hearing it.

First thing, check your engine oil on the dipstick. Does it do it at idle, in neutral, the car not moving? Increase in frequency with increasing rpms in neutral? Any difference in gear vs in neutral? Any difference in gear under heavy load (like rapid acceleration or going uphill) vs light load?