He walked in the ways of the kings of Israel and also made cast idols1 for worshiping the Baals.
References for 2 Chronicles 28:2
He burned sacrifices in the Valley of Ben Hinnom2 and sacrificed his sons3 in the fire, following the detestable4 ways of the nations the LORD had driven out before the Israelites.
References for 2 Chronicles 28:3
He offered sacrifices and burned incense at the high places, on the hilltops and under every spreading tree.