Hmmm...are you sure you don't have the O/D turned off??? Not sure on Maximas, but a lot of auto trans cars will have a little button the side of the gear knob that will turn off overdrive..basically waht this does is eliminate your 4th or 5th gear (whichever one is your overdrive gear). It's going to hold the transmission in the next to last gear, so you'll be running at a higher rpm. Look on your dash and see if there's an indicator light indicating the the O/D is turned off. You want it turned on