When I drive down the highway and accelerate to gain speed. I let off the gas when I reached my speed, but for some reason the engine will stay at a high RPM either before it shifts again or at times will just go where it should be. Could this be a transmission issue or throttle issue?? Maybe bad communication between the transmission and computer?? It has the 5 speed transmission in it.

 

See if the throttle plate is gummy around the edges for starters.

 

No it is clean around the throttle. Was a Police Car so in all everything is clean under the hood for the most part.