Where is the low pressure port on 2001 Nissan Frontier?

On a 2001 Nissan Frontier, the low pressure port for the air conditioning system is typically located on the larger diameter aluminum line, which runs between the evaporator and the compressor. It is generally found near the front of the engine compartment, close to the passenger side. The port is usually covered by a plastic cap that may be marked with an "L" or a blue color. Always ensure the engine is off and the system is not under pressure before attempting to access the port.