if you mean highest setting being the fan speed, then the problem is most likely the fan speed resistor located in the blower motor box area
Yes
in the glove box
R-134a
YES
no they are to big
Under the hood, on the passenger-side of the firewall, down low & just above the catalytic converter.
you can purchase a repair manual for your vehicle from most auto parts stores, or try autozone.com and look under component location or repairs for the Nissan Pathfinder.
Yes
A 2008 Nissan Pathfinder has 15 mpg.
The 2010 Nissan Pathfinder has .
1999.5
Check