This is western cedar borer. It is not of concern as it's native and attacks dead and dying trees - often drought-stressed arborvitae in sun-exposed lots.
Emerald ash borers are about half the size of golden buprestids and a quarter as wide. There is a guide to look-alikes here: https://www.oregon.gov/oda/programs/IPPM/SurveyTreatment/Documents/EABLookAlikes.pdf

Josh Vlach
Aug. 11, 2022, 1:23 a.m.