I'm 99% sure that setupcode tuner/Audio 0176 is the correct codesystem. It is very difficult to find a Yamaha RXV-model that doesn't respond on this code.
However, the reason that many people struggle with the setup for a Yamaha AMP or receiver is because so many different models use this setupcode and that there are different options for some functions. On hifi-remote.com you can find the AFC (aka Key Magic codes) for some functions :
[Link: hifi-remote.com]For example for "Power" there are 2 opions, some Yamaha's use On & Off and other use a Power that toggles. Of course the URC-8060 can't guess if your RXV450 use On & Off or the Power toggle nor which other functions it needs, so it simple takes about 30 of the most common functions of 0176 (the complete 0176 might contain +/- 100 functions), so often the pre-picked Power function doesn't work.
My advice:
Check 0176 by testing if the Volume Up & Down keys work correctly. Please make sure the "Volume Punch Trough" (aka Volume Lock) is disabled, otherwise you might test if your Yamaha does respond on the Volumefunctions of your TV :)
Also make sure there aren't any learned keys in Audio mode. If your want to be sure about that, you can erease all learned functions and disable "Volume Punch Trough" by pressing:
"Magic till Rabbit ; 980" The URC-8060 will confirm with a double doubleblink.
If you have confirmed that "Volume" does work, check the numberkeys, it will work for (most of) the inputs. Then check the other keys. You will probably notice that some (or if you have bad luck, many!) keys are missing, you can add thes keys with learning or Key Magic. For Key Magic you will need the Advanced Functions Codes, some are included in the link above and if you would like to have all functionscodes, contact OFA customer support.