Three things that are fairly easy to DIY: check all hose clamps for tightness, spark plugs for any signs of fouling, and running a bottle or two of Techron through the fuel system (or use a known high quality 93 octane fuel for a couple of tanks). It may be worth getting a tune for the improved gas mileage that many have reported, but most likely you'd be running 93 fulltime at that point.