Help with CEL P0303

[motopilot]

Helo, We have a 2002 Protege LX 2.0 with 105K on it. I put new plugs in and an O2 sensor about 4K ago. We have been noticing a rough idle while sitting at lights which has turned into rough driving while on the highway. Almost like a clogged FI. The CEL light came on and the guy at autozone gave me this code P0303 which said #3 cyclinder misfire. I am going to check the plug but does anyone else have any ideas? This is our daily driver so trying to get it fixed. Also anyone in the Orlando / Deltona area that could be of help would be great. Have to do timing belt soon too (was done at 61K) but was going to get he dealer to do all of that (water pump, pulleys, etc.). Have off this week so trying to get this done.

[Chef]

Coil's...check the coils reverse them see if the misfire switches cylinder misfire

[motopilot]

OK I think i fixed the problem. First thing I did was just check everything. When I pulled the #3 plunger from the plug slot it was cover in black sut of sorts. When I unscrewed the plug I noticed that it was not all the way tight. I pulled the plug off and it too was black cover. I cleaned everything up and replaced the plug with a new one and tighened down the plug. Started up right away and so far not any problems (just did a quick run to the market). I am wondering if the plug not being tighened down properly was the problem. I am however going to replace the coils and plug wires as well. Everyone seems to agree that they should be replaced (105K). We have not had to really do antyhing to this car so I do not mind a little maintence now to keep her going another 100K. Can I get these items through SU? Do not need any aftermarket stuff just OEM would be fine.

[Chef]

we can get you coils and wires yes..