Where is the ac low pressure port on a 2004 Nissan Frontier?

On a 2004 Nissan Frontier, the AC low pressure port is located on the larger diameter aluminum line that runs between the AC compressor and the evaporator. It is typically found near the firewall, on the passenger side of the engine bay. The port is usually capped with a plastic cover, which can be removed for servicing the AC system. Always ensure the engine is off and the system is not pressurized before attempting to access the port.