98 chevy 5.7 code P0306

I have a 98 chevy z-71 w/ 5.7l engine. It runs like crap!!!! Poor fuel mileage and very rough idle and just runs crappy all around. Put scanner on it and came up with P0306. #6 engine misfire????? is that correct?? pulled #6 plug and it looks to be normal. If anybody has any ideas please help. Thanks. Also have overheating problems with a 95 eagle vision with 3.5l engine. I posted thread for that one also if you can help please do!!!!!

Thanks
Mike:banghead:

Looks can be deceiving. You need to check for spark with a spark tester instead of just grounding the spark plug. I can't imagine spark testers are expensive, they plug into the plug boot and attatch to a ground. It will tell you if you have spark getting to the plug. If you are getting close to 100k miles it might be time for a tune up. Lately I have been seeing a lot of vehicles coming in with misfires that are just bad plugs that may not look bad at all.

The plugs, wires, distributer were replaced about 2 1/2 yrs ago. I think i will probably do a tune up on it this weekend. If you have anymore ideas please let me know.
Thanks