Rufus is sick!

Hey guys, I need help. Old Rufus, my 1996 Cherokee Country is pushing 226000 miles. I am pretty sure i have an exhaust leak, and need to change am O2 sensor and a ball joint. Other than that he has been trouble free for 100000 miles. Now i am noticing a sound i don't recall hearing, i was wondering if anybody could give a listen and put my mind at ease.

http://sdrv.ms/Vm9rr9

The sound is easily noticable in the cab, so that's where I recorded it. It isn't as bad outside, but the fan noise covers quite a bit. I thought sounded like valve noise but I'm not sure.


Thanks!