hi, i have discored i have a faulty injector, i tried re codeing them first for arguements sake, so i did a leak off trest and for sure one of the injectors are leaking no.2 not a drop of fuel came out the others, im now sourcing injectors, do they have to be the same make and model as the previous or can they be a different brand. is there any others i can get apart from delphi or do they have to be delphi