Here are my thoughts. If the system is lean, chances are you are having problems with getting adequate fuel supply during ignition, which may cause problems with mis-fires as well. My guess is that you have a fuel supply leak or a bad injector. See if you can get a diagnostic done by the dealer to see what's up. Chances are, the more codes you have, the more likely you are to find the problem. If you are more of a do-it-yourselfer kinda guy, checkout
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