i got a 00 gtp and the only mod i have is a DIY FWI and ever since i had a cracked plug and switched to autolite APP104 double platinums my car misfire when im WOT but when im just cruising around its fine.....could my car not like the platinums or a bad wire? because it misfires pretty bad i get on it and at about 3000-5000 rpms it just studders and then jolts forward and misfires and then jolts again i got smoked when i ran an audi the other day and had this not happened i know i would have ate his ass lol so i wanna fix it any solutions lemme know please thanks