misfire on cyclinder three and running lean on bank one and two

Here is some inf for the misfiring cylinder: http://repairpal.com/OBD-II-Code-P0303 and for the lean running issue: http://repairpal.com/OBD-II-Code-P0171-and-P0174 I would focus on vacuum leaks, especially around the #3 cylinder intake manifold.

Try just the plugs and that number three coil, if that doesnt help look at the o2 sensers

try the pcv and the tubing on the passenger side vaive cover and follow it all the way to the back of the intake. also check the pipe on the driverside valve cover that runs to the airtube just b4 the throtlebdy