46,000 miles seems to soon to replace oem shocks muck less koni
Does not sound right, should have made noise with old tires also. WHERE TIRES BALANCED
PROPERLY.MAYBE ONE are more OF THE NEW TIRE IS OUT OF ROUND THIS WOULD CAUSE ROUGH RIDE . The koni shocks have a lifetime warranty to original buyer may do some searching and find buyer if possible, if shocks are bad.
I would have problem checked by some one else, ALso Shocks should be replaced. in pairs

Good Luck