Help Please Posted in wrong area to start....

I have a 1994 subaru legacy 2.2 liter turbo engine and am having issues I hope someone on here could help with. Here goes... When I start the car after a rainy or humid day it will start fine, but whenever I put it in reverse or drive it starts to spit and sputter like it wants to stall out. This is the only problem I have had with this car that was not an easy fix. I would really like it if someone could help me. I have had the car for 5 years and would love to make it my project car since I have gotten a new car. Any help would be useful.

Also I have replaced the plugs, wires and ignition coil.

on a dry day with a few day without rain it does perfectly fine. It is a hassle to get it to keep going on a rainy day. I may be doing harm to the motor but before I got a second vehicle all I could do is pump the gas and keep it moving after about three miles of driving the problem stops usually for the whole day until I let it sit say over night or a day or two. Also I am sorry I didn't put this in the first post, but As I pump the gas the motor has a horrible back firing problem ha.