car trouble

ive been looking but i dont have a clue how or where to poke the 4gauge wire throught the firewall btw i have a protege 2002 es NEED HEP PLEASE THANKS IN ADVANCEE

Hey everyone! I got my 93' mx6 about 5 months ago from a little dealership that sells used cars. It has about 180k miles on it and runs fairly well. Recently though...I'd say from about 3 weeks ago, it's been having trouble starting and would shutter in gears. Replaced the spark plugs, which...