It would seem that when I disconect my batt then reconnect it my gas mileage goes to hell, I put a CAI and was getting great milage ( I thought my gas gauge was broke ) then I disconected my battery to mount my battery switch, now its awful again, is this normal?
I went to my first autocross last sunday cant wait to get involved.

 

I would think it would be possible since the PCM needs to relearn the engine again. Maybe you are heavier on the gas after the reset as well.

 

I second that^

The PCM needs to relearn the engine and your driving habits whenever a change is made. My 99 gets erratic mileage at times too. I usually average around 40mpg but the last tank was only about 32-35.