Transmission problems????

[Sidewinder007]

I just changed my EGR valve and had no transmission problems until after the changing of the EGR valve. Now the transmission shutters while in reverse backing up slowly. The tranny acts as if it won't go from 4th gear to 5th or 6th. Does anyone know what is going on before I take it to the dealer? The truck has been tuned since 2000 miles and has around 52K on it now...

[Sidewinder007]

Come on guys would it help if I give the T.C. that have come up...
T.C. are as follows : p2453, p0766, P2703....I need some help from any mechanics that can tell me what happened. I had only change the EGR valve and then went to drive the truck and up until that time I had no problems with the transmission until after that first drive after the EGR valve being replaced.. . HELP HELP plz......