-Last night, filled tank in 2000 Sephia with no previous signs of malfuntion. Drove home and parked it for about an hour.
-Upon ignition, engine sputtered, but idled OK. During acceleration, ran very rough. After about three blocks, turned around and drove the trusty Volvo for 20 mile trip instead.
-This morning, drove Kia about 2 miles to buy new fuel filter. On the way, noted that sputter occured in mid-throttle. Replaced filter, and restarted.
-Let idle for several minutes and increased throttle. Sputtering still occuring.
-Car has 52K miles. Bosch plugs and K&N filter only a few months old.
What next?