After a highway cruise the other day my 91 GEO tracker auto started surging, stumbling, and back firing at low speeds and RPMs.

I replaced the following
Plugs
Wires
Cap rotor
Fuel filter
Removed cat
Poured in a bottle of HEET to make sure no water in my gas

With still no luck. It seems to run ok at high speed and rpms. I also noticed some condensation coming out of my exhaust pipe. Not smoke but literally water dripping slightly when I first start it. The check engine light is not on either. Any suggestion I would hate to take it to the shop. Thanks for any and all help!

hey i have been having the same problem. try disconnecting the electric plug on your map sensor (located on left top side of your firewall) this should make it run without surgeing. then if that fixes it, you probably have a bad map sensor. the hard part is finding a good one. they retail for $250.00 at AutoZone. luckily, i found one at a junkyard for $5


good luck, hope it helps