after looking through all the threads i could not find one similar to mine. i have a 94 2500 2wd 318 204000 miles (i know its an odd setup but it has plenty of pulling power). when i start it up it immediately has a kinda rough loud idle and runs lean then after 5 min or so its like somebody snaps their finger and the idle smooths out and runs a little rich. if i try to drive it cold it hesitates real bad and has no power at low rpm and has a hissing whistling sound i can hear in the cab. once it warms up till the thermostat opens it has and intermittent miss about every 5 seconds. i got a new plugs and wires, o2 sensor, coolant temp sensor, computer, and i beat the crap out off the egr to free it up. that took care of all the codes that it was throwing but i still got the problem. it did burn quiet a bit of coolant last winter but it has not this year. im going replace all the gaskets on the top end here soon. im going to check if the plenum gasket is leaking today and clean up some of the sensors and get some resistance readings. i just wanted to get some feed back to see if anyone had the same issues or if any of ya got some idea's.