HIGH IDLE on 2001 Nissan Maxima

first, I'm losing about 2.5 gals of gas per tank. I use to get approx. 370 mi p/tank, now it's 265 mi p/tank. the engine idles high around 11 to 1200 rpm in park. Around 900 rpm in drive. Somebody told me to change out my idle speed control motor. Another said change the idle speed sensor. HELP!!! GAS AIN'T GETTING ANY CHEAPER. PS... If you live near the 21061 area and know of a good mech, pls let me know.

Asked by for the 2001 Nissan Maxima
Really need to get the codes from the computer system, a high idle can be caused by a multitude of things, like rich running, a bad coolant temp sensor etc, etc. And, all these things would cause a loss of fuel economy.
here are some shops to consider: