2002 troubleshooting feedback

Hi All,

My 2002 Sonata (102,000 miles) has been sputtering and not performing well lately. I used a OBD-II scanner and it came up with p0305 and p0274.
P0274 Cylinder 5 Injector Circuit High
P0305 Cylinder 5 Misfire Detected

I proceeded to change out the plugs and wires, the plugs had a lot of carbon on them and the ceramic was all but gone. After the tuneup, the car started better, but it still ran rough and applying gas made it sputter and die.
I now am considering changing out the coil pack and/or mass air flow sensor, and have a couple questions.

1. Do these two steps (coil pack and air flow sensor) seem reasonable? Are these likely culprits since I already changed out the wires/plugs?
2. Which part would you try first?


Thanks,
Kelly

You need to be looking at the cylinder 5 fuel injector before you mess any more with the ignition. The P0274 is likely causing the misfire code. Here is the flow chart for diagnosing P0274, and any injector high or low resistance codes.

http://i101.photobucket.com/albums/m52/jjnance/Work%20Related%20Pictures/efac612a.gif