i have a 97 tj, 2.4 li. 4 cly. recently it started bucking really badly whenever id go over small bumps like on the highway. the tach also went up to 5000rpms randomly while driving. read up on it and found it couldve been the crankshaft position censor. replaced the ckp sensor and it was fine. that is until i drove it again and the bucking was worse than ever. i could get only to 5mph and maybe 2000 rpms. i fandangled it down to the auto shop where they found the ckp had been installed wrong so they replaced that. didnt work. they thought the wiring harness to the main computer and the wiring with that was bad. they replaced that and as they were taking it for a test run, it died and it hasnt run since. it has had a previous history of an exhaust leak from a broken bolt in the motor. im not sure if it has anything to do with my problem. i just want my jeep back!! input??