Air mass flow sensor

No need. Just turn the key off.

Okay. Thank you.

Autozone says to disconnect.

You do not have to remove the Negative cable to replace it, but you should. Because you want to replace the Learned fuel value in your ECU. Removing your negative cable from its terminal for at least a hour, (overnight is guaranteed to reset it.) or if your up to it, you can also remove the negative and positive cables and have them touch. Your draining all the power in the ECU, Resistors and Capacitors store power even after the negative cable is removed and they need time to drain. Waiting the time, or crossing the streams (Who you gonna call?? LOL) will do it. When you have done that, and replaced or cleaned your MAF sensor. you will have also reset your learned fuel values, now you have to relearn. You can either Drive your car.. For a drive cycle. Google your make and model and drive cycle.. and when that is done. your Fuel values should be good. IF your car spits or sputters, WOT.. (WIDE OPEN THROTTLE) Floor it.. and haul some ass. You want the car to be strong.. and not weak.. and it will learn that here.. An you should be all set, unless your driving a make and model that has a TSB where value are not relearned due to a TSB, (tech service bulletin) you instead will have to drive your auto to the Dealer ship and have it reprogrammed and it will cost you. Disclaimer: While I am a Master Nissan Service tech, and a Certified ACE mechanic. I am not working for you or on your auto. I am giving you general knowledge and what you do with that is at your own risk. I take no responsibility for your automobile.