girlfriends 2001 accord has cylinder 1 and 4 misfiring. also alond with cyl 1 and 4 engine has code saying random cylinder misfiring. i changed sparkplugs, seemed to help a little bit, i changed oil only cz it was past due, and put fuel injector cleaner. i dont think the head gasket is bad cuz its not leaking coolant oand theres no smoke out of the exhaust. so a week ago the engine maintainence light came on, then when the engine started being rough and idling rough the check engine light started blinking....any imput? thanks also is this a BIG problem?