First off I just want to say that I am new here and I really hope yall can help me out. I got a 94 dodge ram 1500 with the 318 and out of nowhere she started wigging out on me. it is shifting fine and aint leaking fluids, but i got this hissing sound that seems to be coming from the front driver side area. That faster it goes the louder it gets.(I think is a exhaust leak up near the manifold) The problem im worried about is as follows; it happens going 35 and its happens going 70,(Although i made from autozone, 5mi. cruising 50 without an issue. Only time since it started happening) itll start to slow down, it went from 60 to 50 without me moving my foot until i tap the gas, then itll get back up to speed and start all over.The only thing ive done to it(other then drive it) is change the plugs and wires. The wires were from a different car but i cant see it having that kind of effect. my rpms will bounce up and down in bout a 300rpm range.(depending on how fast i go) and i can move my foot almost an inch with no effect(when its acting up). if I tap it a bit i can get it up to 60 but then after a couple of min the engine will go quiet like i let off the gas and start to loose speed, then about 10sec later itll jerk and start going again. I already checked the codes, one for a o2 sensor and one for an internal temperature sensor in the tranny. The tranny thing has been on there for a year, never an issue. I already unhooked the 02sensor from the cat, helped but didnt fix. I checked the fuel pump and the asd relays, both clicking. Test the fuel pressure, solid 38, idling and going 60 and while the problem is accruing. batterys strong, alternator is quiet and all the gauges seem fine. Oh yeah, all the vacuum lines look to be in good shape and after about a week of this prob, maybe 40mi later. now its starting to die on me as I pull in and out of my driveway. The guy at autozone told me it sounded like a ICM problem and the guy from o'reillys said something about the transfer case locks up after so long to cut down on drag and that it was trying to do that, but having issues. Im stumped, Well I appreciate yalls help if you have any ideas