as for idle, way low, should idle at 750 whether in park or gear. my suggestion is fill the tank with the highest octane around you, 92/93 and reset your computer or over head console and take it for a long highway drive. put some miles on it. with these short trips, a lot of carbon has been building up and it may need a good beating to help clean it out, and don't be shy with opening it up every once in awhile. also check your tire pressure, I normally run 40 psi. less rolling resistance