> the charge location should have a yellow cap with
> r134a on it back left area of the engine

NO. The 850 low-side charge point is just aft of the passenger side headlight. The cap is black and marked with a torque rating (7 NM).


> a shop usally charges 100 bucks, not sure what they do for that
> other than what the $25 kit can do, perhaps than drain the system
> first.

A shop will do the job most correctly by evacuating the old freon and replacing it with a *measured* amount of new freon. Your recharge approach will work, but it's impossible to get it perfect with only a low pressure guage.

Gerald C