The Nissan Path

hey guys any help would be greatly appreciated things i've changed ..... temperature sensor plugs wires cap rotor fuel pump coil fuel filter and i've unbolted the exhaust before the cat. The truck starts up and runs fine and drives fine until it warms up....when it warms up it begins to sputter and idle rough and will not rev over 2200 rpm and when it does hit 2200 it backfires like a son of a bitch .... does anyone have any ideas ?!

I recently read that the crank sensor, if bad, will fail when warmer. My 1990 is doing the same thing....gonna go to the salvage yard and get a used alternator and try swapping that out today. I'll letcha know how I make out.

Bryan