1997 Toyota 4Runner engine bogging

Hi,
My 4runner seems to sputter, bog when I accelerate from 3rd to 4th, 4th to 5th gear trying to obtain higher speeds, and/or while driving up hill, check engine light came on and code suggested # 3 cylinder misfire. I have changed plugs, wires, O2 sensor, and it still does it. Also, tried fuel injector cleanor as well.

What do you suggest is the problem? I'm thinking of changing the fuel filter?


thanks.
denis