I found under Piloting (Space and Planetary) that rules say chases are resolved with an opposed check. However, in "The Chase", page 241, says it's a competitive check. Is this errata?

Both are correct. The opposed check is for a simple chase, the comptitive is for a combat style chase to allow for shooting and such.

Thank you for the answer but where is this explained in the corebook?

Its not explicitly stated, its one of those between the lines things. The gm has to determine which version makes the most sense. If you just want the players to run the opponent to ground you want the normal opposed checks. If you want to have the players chase and shoot down the enemy scouttrooper before he can report back you want the chase.

Also if you have a solo game you probably want the second more often as it allows for the player to do more then just opposed roll after another.

I like that, thanks.