after everything I replaced , what else could be causing my misfire on the #2 on 1996 Mazda B4000

I have replaced the spark plug, spark plug wires , coil pack and fuel injector. but my scanner still detects a missfire on the number 2 cylinder. What else could it be.

2 answers 2 comments
Low compression, vacuum leak or no injector pulse to that injector. Code P0302 to start with?
yes P0302
Ok, check the 3 things i posted.
poss wiring to injectors or coil pak