I would start with coils and plugs as possible causes of the misfires.
If you've never replaced your plugs, they should probably be done. There are plenty of DIY's if you want to give it a shot yourself. Not too difficult, but the rear two are supposed to be a bit of a challenge.
For the coils, just figure out which cylinders are 7 and 2 (quick search online). Then swap the coils from other (no error) cylinders, clear the codes and drive till the codes come back. If the misfires move to the cylinders where the suspect coils are, then you've solve your problem (or at least one of them). This should be very easy and cost you nothing. Probably the first thing to do. If the codes remain on the same cylinder then replace (at least) those two plugs, clear codes and drive till they come back. This will elliminate some potential problems that are related to basic maintainance anyway.
Hope this helps...
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Last edited by Mulchman; 11-29-2012 at 08:12 AM.