93 k3500
 

I'm far from a pro, but here it goes. K3500 sputters and dies when I put it in D or R from a stop. Also, if I sit at a stop in gear with foot on brake it will die. Here's all that me and shop help did.
New, plugs, wires, cap, rotor, fuel filter, Amzoil Power Foam.
Helper got his scanner on it and it pointed to an EGR problem.
We replaced IAC, EGR motor, EGR valve. No improvement.
At 200K everything else runs great.
What's the next step?