John Gill Commentary 1 Kings 15:12

"And he put away the sodomites out of the land, and removed all the idols that his fathers had made." — 1 Kings 15:12 (ASV)

And he took away the Sodomites out of the land
Which were in the times of Rehoboam, (1 Kings 14:24) , and continued in his father's reign; those he took away, either by driving them out of the land, or by putting them to death according to the law of God, (Leviticus 20:13) even as many of them as he had knowledge of, for some remained, see (1 Kings 22:46) ,

and removed all the idols that his fathers had made ;
or suffered to be made, as Solomon, Rehoboam, and Abijam, see (1 Kings 11:7) (14:23) (15:3) .