To add refrigerant to your vehicle you must first locate the low side port to your ac system. There is a great web site www.idqusa.com that can help you locate the low side port on most vehicles along with helpfull information about a vehicle ac system.
R-134
i believe 2004
Depends on the size of the engine and what part you are using, but in most cases yes.
You can put Freon into your 1997 Nissan Pathfinder from the low pressure port. Connect the Freon bottle to the port. Release the Freon into the air conditioning system.
Yes
check your answer
Are you sure there is one? Ford products typiocally have one, but I am not aware of Nissan having one.
This information can be found in your owner's manual.
Which do i hook to to charge the freon in a 2004 ford expedition
R134a
R134a Refrigerant
Put 4L in and then check it. Most likely 4 to 4.5L will do it.