for a injector leak you need to see if fuel pressure bleeds off while car is not running. Tee a gauge after fuel filter ( temporary) then key on. thats you pressure. key off, see if pressure stays there. if it drops quickly - you are leaking some where.
beyond that, are o2 sensors working when you do the self test on the ecu? coolant temp sensor in specS? if the ecu "sees" cold temps you will run rich