The sniffer is actually good for locating leaks that you can't normally see with the uv dye such as from the evaporator or expansion valve which you can't see unless you remove part of the glovebox and dash. If it sniffs refrigerant in that area, then you know that you have to tjear the car apart to get to the evaporator.

BTW, I just had my alternator replaced at around 70k miles.

__________________