I have a 2001 Chrysler Sebring. Since 2002, the engine will occassionally miss or shudder. There is no one instance when it does this; it does while idling, cruising, excelerating, etc. It does on hot days, cold days, humid days and dry days. Upgraded gasoline does not seem to improve it, oil changes do not improve it. It is worse when the tank is near empty. Flushing the transmission system did not improve it.
Oh yeah, I’ve tried Gumout and Lucas Oil’s fuel injector cleaner, but they don’t help either.