John Gill Commentary 2 Kings 14:3

"And he did that which was right in the eyes of Jehovah, yet not like David his father: he did according to all that Joash his father had done." — 2 Kings 14:3 (ASV)

And he did that which was right in the sight of the Lord
. At least externally, and at the beginning of his reign:

yet not like David his father ;
not with a perfect heart, with that sincerity and uprightness as he did, see (2 Chronicles 25:2) ,

he did according to all things as Joash his father did ;
who at first reigned well, and then fell into idolatry, as this his son did.