so I have a 02 b3000 that was given to me. had some issues when I first got it. I got those issues worked out only to ride right into more. the thing is running like trash as if to be struggling for fuel or air one. has a new maf,coolant temp sensor,tps,canaster purge valve, no vacuum leaks, cats are not clogged, 02 sensors are good, idle air control valve, crank position sensor, thermostat all been replaced. it starts every time no issue get on the road runs fine till it hits about 3000 rpm then the fun starts.acting like its gonna die but doesn't push the gas to the floor does nothing but sputter sometimes won't go above 20 mph but 5 min later will hit 60 no problem truck has no egr valve fuel filter is good gas is good any ideas would be appreciated

 

Check your plugs and coils, injectors, throttlebody, air filter, and wiring connections, I'd say. Give your tb a good blast of carb clean too, while you're at it.

 

Your game of parts darts is getting expensive. I don't see in your post where you have had it scanned. Do that and post the results.