reason why i say that is the viper 5901 has a remote start option to it and the problem with a manual car like mine which is a crossfire 6 spd was the viper alarm has to see a specific sequence or it will not remote start the car.
the door locks and factoy arm/disarm was feeding back into the brain once the car shuts down and tripping the sequence, diode isolate took care of it and honestly HOW MUCH DO DIODES COST.
you are a mecp installer diode isolate will not hurt your install, yeah it adds time but that is the point of being professional and less time wasted trouble shooting.