ok...i checked for code 55 and didn't see anything but i might know whats wrong code 4 .. CKP Sensor (Crankshaft Position Sensor) defective circuit or unplugged / defective sensor... did you do ALL of the wiring need to convert from a dpfi to mpfi... i am pretty sure that, that sensor is located in the dizzy and is need for the engine to start...i had someone run the wrong wire there once and it wouldn'
t start... it took me long as hell to figure it out...