-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?