Did a tune-up had a code 16. Optispark/Plugs/Wires. Car runs great while driving but when stopped in Drive it sputters/shakes and acts like it wants to stall out. Changed IAC/Fuel Pressure Regulator/Coils. Then had one Fuel injector spraying out gas continuously so changed the fuel injectors. At this point at a loss as to what to do? Thanks for any suggestions you might have.

 

Make sure the EGR valve isn't sticking open.