Yup a good tune-up does wonders for restoring power and getting better mpg's. Don't forget to change your fuel filter, a clogged one will rob you of some power and lower your mpg. Also if you have over 75k miles on your car a new 02 sensor will help too...
Also, it may be a good idea to clean the throttle body. I was taking my engine hoses off and scrubbing them up (didn't realize the dirt on them compared to the new look under the clamps.) Anyway, the circulator hose from the throttle body, I suppose that's what it is, when I removed it the port on the engine was almost closed off.
I'd suggest reading this article: http://www.se-r.net/engine/clean_throttle_body.html
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