What kind of fuel are you using?
If you're using Unleaded 91 or E10, try running a couple of tanks of Vortex or V-power through it, or even a bottle of engine cleaner, before you take it to a mechanic.
I had the same problem that my engine was gutless and chewing too much fuel, I'm running nothing but the expensive stuff through now, and I find that it makes a huge difference. Of course, it doesn't hurt to get your injectors cleaned every now and then
(235000 btw).