You most recent post is confusing? Are you saying you replaced two strings only? And if so which ones?

In standard tuning the strings should be tuned EADGBE thickest to thinnest. or EBGDAE 1 to 6 by guitar string numbering convention.

012 & 112J & V Pacificas only have single string tree. It's purpose is to assist maintain stable tuning by facilitating the correct tuner mech to nut string angle and thus tension on a six in line Fender style headstock common to many guitars including Yamaha's Pacificas.

The PAC012, PAC112J & V all share the single pressed metal bent wing type screwed onto the headstock with a woodscrew. After you've restrung, the B&E strings should be routed under its wings as illustrated in the image you posted. Be sure not to overtighten its woodscrew as the tunnels of the wings need to be able to self-align with the string routing from nut to tuner mech so as not to friction bind.

Another point of note. The 012 nut is Urea not TUSQ. Either when all strings are off, or if fitted lessening tension and moving the strings aside temporarily, lubricate the slots with either a the tip of a lead pencil or by applying a minuscule fine application of powdered graphite. This will assist with stable tuning.

[u]Re the buzzing[/u].

Assuming you've changed nothing else [u]including the string gauge[/u] (?), (i) check the string routing under the bent wing tree guide. (ii) Check the strings are in the nut slot/s. (iii) Check the strings are routed correctly in their respective string saddles (6) at the bridge.

If all you've done is change strings for new strings of the same gauge, [u]if there was no buzzing before there shouldn't be now[/u]. The string height (action) should be the same, not requiring either a truss rod (neck) adjustment nor saddle height (two grub screws in each saddle) adjustment. It's a vibrato bridge, and not a great one on the 012, so ensure the bridge plate isn't floating. Those model Pacificas usually come adjusted from the factory with the bridge block tension spring screws at max tension effectively locking it down flat against the body for stable tuning.

If it's still buzzing try fretting each string one at a time at each fret working up the neck and see where it's buzzing. If you find the [u]string buzzing at a particular fret[/u], put a steel rule on the three adjacent to determine which fret is high/low. If it's a near new Pacifica, the frets shouldn't be worn but level.

[u]Assuming newish and frets in good condition, if all the frets are buzzing[/u], your action is now too low for whatever reason. Check the neck. It may need minor truss rod adjustment. If it's straight it doesn't, so adjust the string heights (action) at the bridge to spec with the saddle's grub screws. You'll have to reintonate afterwards either way.

If all of this makes no sense to you or fits neatly into the too hard basket, take it to the shop.