I really don't know what it is. I have had a tune up recently and all, but I am getting really bad gas mileage. From a full tank of gas, I can maybe get 200 miles. All I have done engine wise is magnaflow full cat, ngk blue spark plug wires, and an AEM CAI. I do occasionally get on it pretty hard but that shouldn't make it where I get that bada gas mileage. The engine's got 123K on it. Anybody have idea's on what could be making me get such bad gas mileage. I'd really like to find out because gas prices going through the roof and the funds are running low. Any help is appreciated, thanks in advance!

Joe