Diesel Bombers - 95 Powerstroke throttle response

I just purchased a 1995 power stroke 5 speed 4x4 with 139,000 miles on it. I've noticed in the mornings when its cold the truck runs like a bat out of hell. As the truck warms up the throttle response starts to become sluggish until the turbo kicks in around 1500 rpm. I've changed the glow plugs, UVCH and changed the oil. Does anyone have an idea of what could be causing the slower throttle response after an hour or so of driving ? Any help would be much appreciated. Does anyone know where I can get a code reader. All of the ones I have only work on 96 and newer. My truck has the OBDII connector in the cab on the passenger side, I am also contemplating installing a 96 PCM so my scanners will read and perform tests.