Pic of MAF
#2
well if you have an LT1 its right before the elbow, if you have an LS1 its behind the bellows of the airbox. Pop it out, unscrew the 4 screws (T20 pattern), and spray it with MAF cleaner
#4
Yeah, but he wants to spray the front of the MAF through the screen to get the sensor wires cleaned, thats where the incoming air is measured.