This verse continues the metaphor of life as walking on a way. For literally, 2 Kings 21:22 reads: He abandoned the Lord, the God of his fathers, and he did not walk in the way of the Lord.
Nothing is mentioned about Amon’s political significance, and only a little about his religious life. Apparently, just two years of reign was too short for any political actions worth mentioning, but in that short period of two years, he let it be sufficiently known that he was not walking in the way of the Lord.
22 He abandoned the LORD, the God of his fathers, and did not walk in the way of the LORD.