lifters will tick if the oil hasnt been changed regularly, as old oil sludge gets stuck in them and stops them from performing as they should
injectors tick normally, in fact, a nice injector tick shows signs of good health in the injectors
you will tell the difference as you will hear the lifter tick from inside the cabin, you wont hear injector tick inside
if its your lifters that are ticking, new oil wont fix this, you need new lifters, or you can do the tedious task of taking them out, pulling them apart and cleaning them, i recommend just getting some non genuine lifters, as genuine ones will cost you your left testicle.