After warm up my equinox starts to surge while stopped at a red light and will go into limp mode. Only occurs after 20 minutes or so of driving. It drives perfect at highway speeds and drives perfect at lower speeds, Only acts up when stopped.
I have replaced all fuel sensors, high pressure fuel pump, ECM, and dealer rewired harness to high pressure fuel pump from ECM thinking it was a voltage problem. I get code P228D which is fuel pressure regulator exceeded fuel pressure, pressure too high. Dealer states new High Pressure Fuel pump should have solved this. Does anybody have any suggestions?

Scan ALL modules for codes. It will have code(*) if limp mode was initiated.