Acer negundo, colloquially box elder.

I agree that it has a bad infestation of scale insect.

Scale insects have a hard covering on them which protects them from insecticides. So you will have to scrape them off and then spray the tree with insecticide (provado is generally recommended), to try and get the juveniles which have not got the hard covering yet.

Acers can be a bit fickle. You may yet lose it. I've lost a few over the years, though Acer negundo is rather more robust than japanese maples, which are the ones more easily lost.