Car acting funny...please help!

ok...this is probably the 3rd time my Jeep (93 cherokee sport 4.0 HO) has done this in the past month...I'm driving down the highway at a steady 85mph.(it only happens when im going at a steady speed, but only at a fast speed also) and after of about 5-10 minutes of the steady speed, my car starts slowing down. The first time this happened it scared me-I accelerated, and it stopped. But it happened today again, and just out of curosity, I kept the pedal at the same spot...didn't move my foot...so it started slowing more...going 85, it slowed to 75, then kinda started bucking...I don't wanna say it was puttering, because the engine wasn't shutting down...but it was...bucking heh...I really don't know whats wrong, and its really bothering me. I changed the TPS, put in fuel system cleaner, and changed the oil and oil filter, and nothing worked. Whats Wrong??

First, change the fuel filter. It sounds like it is partly blocked and has restricted fuel flow.

Second, could you tell the rest of us what highways you feel safe and secure enough to drive at a steady 85 mph?

I live in south florida, and at some area's on 95 the speed limit is 70-75...so when I'm going 85, people are still flying by :-/

I live in south florida, and at some area's on 95 the speed limit is 70-75...so when I'm going 85, people are still flying by :-/
Maybe they are being propelled by Hurricane Charlie/Francis/Ivan :iceslolan

ha...ha lol...when people were fleaing from francis, there was traffic backed up for literally 30 miles on 95, turnpike, and 75...when something happens, they are slow to react lol...but yea...people here are weird...and yes, amazingly, my jeep can keep a steady 85mph...now that I got my new tires, my car feels like its floating when I'm going down the highway :-P

woohoo! problem fixed...replaced the oxygen sensor