Stepper motor some times need replacement its original suzuki cost is 3500 i changed it had RPM dropping serious issue plug plugs and wires also changed cost 8500
but dear stepper motor adjust your timing and fuel consumption in different weather conditions and on different road condition ............. when u go to high hilli areas simple corborator has fix setting it will use more fuel and give less pick ...................... here stepper motor do the magic it automatically adjust according to Oxygen, air , load on engine, radiator and current condition ............................ and give u the best adjustment and ur car will be most effecient in all weather and all type of road conditions.
remove stepper motor and doing T shap cabla etc ................... u actually disconnect EFI function its useless than its better to buy old corborator car
isses need to be resolved with genien parts installation and you wouldnt have problems