P0741 Chevrolet -

Question

2007 durmax 6.6 code only comes on when under load swifts down will not go back in overdrive

Answer 1

P0741 Torque convertor clutch (TCC) System stuck - off

P0401 Exhaust gas recirculation (EGR) flow insufficient

The TCC will not produce any noticable drivabilty problem being stuck in the iff position is why you cannot get into overdrive, Having a EGR code may inhibit the TCC from engaging. What can cause P0401 are ehaust leak , exhaust restriction or a restriction in the turbocharger air cooler. Have P0401 corrected . You may just need a EGR.