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??