2004 Dodge 3500 5.9 with the 6 speed. been having a dead pedal problem. replaced the APP and thought it was good. but started it up this morning and dead pedal. will only rev to about 1200. i noticed after idleing for a bit the pedal will come back as soon as the temp gauge starts to move. codes p2121 and p2127 are the codes are showing. I have replaced the apps with brand new one. what would cuase a dead pedal like that while cold and the temp where i am is an av of 80