1996 blazer 4wd 5sp...misfires and bucks under normal driving speeds...acceleration and deceleration it seems to stop bucking...gas smell is noticable and exhaust pipe is black...also idon't know if this means anything but if i drive it a long distance my right lower leg can feel the heat and the the console is extremely warm

 

When was the last time a full tune up consisting of plugs, wires, cap, & rotor was done?

Also, have you cleaned the MAF sensor, EGR valve, and/or throttle body?

 

just done complete tune up and cleaned egr...maf sensor...and sprayed out throttle body ....also forgot to mention if i'm riding with my window down fumes are really bad and seem like its coming right through open window(just on drivers side)....also someone suggest unhooking IAT sensor...i tried it and it seem to run better for the first couple of miles and then went back to bucking again

also forgot to mention ...done pressure test...reading aroung 56#....with switch on...after letting it sit for a while it dropped to around 52#(3 minutes) but stayed at that pressure until i unloaded it

 

Almost sounds like something is restricting the exhaust (clogged cat), but the fact that it resets itself is very odd...