so i drove down to dallas yesturday from omaha nebraska and half way here i added 6 gallons of 89 octane and shortly after that it started missing and hessitating realy bad and i was told it was because i had a 3.4 pully and ran lean so i ran it low on fuel and filled up with 91 octane and octane booster well it was still doing it so i filled up once again with 93 and it used to only do it under wide open throttle and i check the codes it says missfiring in cylinder 4 so i have changed the sparkplugs and the wires and the coilpack and i did a fuel check and it never got 40psi so only opton i can think of is bad fuel injector? anybody have any ideas, im here visiting famiy and limited on tools and time before i have to drive 600 miles home need advice please
