Nissan 300ZX twin turbo 2002 _ Injectors Replacement

I replaced three injectors so far and a forth one is giving me problems. Should I replace all of them or just the one? Is any place in Toronto that anyone can sugest\refer other then Nissan? Thank you.

Angelo

Whitehead Performance! They deal with injector problems with 300zx s often, they have a special solution for fixing them, give them a call!