Episode 178
On their way to the Battle Pyramid, Ash and friends arrive in Pewter City to find the gym redecorated! Brock's siblings explain that three people convinced their parents to get the gym redecorated to make it look nicer and then they sent Flint and Lola on a vacation! When Brock looks at the inside of the gym it looks just as bad, and he finds out that his Onix has evolved into Steelix! Then, the re-modelers, who are actually Team Rocket in disguise, return with a new Charizard and Aggron given to them from Delibird (and actually meant for Butch and Cassidy) and challenge Brock and Ash to a battle to decide the fate of Pewter Gym!
Aired 18/05/2006EP 178 - Episode 178
Pokémon the Series: Ruby and Sapphire
After participating in the Johto League, Ash decides to begin anew in yet another journey; this time by himself and Pikachu, in the land of Hoenn. Though he isn't alone for long, as 10-year-old May (who dislikes Pokemon, but just wants to come along to see the world) travels with him after Pikachu destroys her bicycle. Ash also meets up with his old companion, Brock, and May's younger brother, Max. Together, they travel along in Hoenn, battling Gym Leaders, entering Contests, and other events on the way to the Hoenn League.
(Source: Anime News Network)