Suddenly my fuel economy has gone to the toilet. I am driving the same way, except it seems like Im missing about 2 gallons of fuel. I used to get around 21 MPG or so and now Im in the range of like 18 MPG. Im wondering whats going on? I had put some cheesy cone filter, and thats when I notice the fuel change, and now I've resently gone back to the stock airbox. And its still the same, anyone got any ideas?