The Amorites appear here as representatives of the old Canaanite nations (Genesis 15:16 note). It seems to be implied here that their idolatries were in the main identical with those of the Phoenicians which Ahab had adopted.
Related Commentaries of 1 Kings 21:26
1 Kings 21:26
26 And he did very abominably in following idols, according to all things as did the Amorites, whom the LORD cast out before the children of Israel.