chipping an mfi erst removes the fuel cut and allows a higher boost setting, if you swap to efi the car can run on different management and injectors and can be mapped accordingly. the standard fuel system on a mfi rst can only produce enough fuel for 17/18 psi of boost, to produce this much fuel the system will also need to be re-calibrated as it does not adjust automatically. when boost above 17/18 psi is required the fitting of a 5th injector is needed.

lee.