"Big Adventure! The Quest for the Fourth Hokage's Legacy Part 1" (大冒険! 四代目の遺産を探せ・前編, Daigōken! Yondaime no Isan wo Sagase Zenpen) is episode 170 of the Naruto: Shippūden anime.
The story goes back to right before the start of the final rounds of the Chūnin Exams. As Naruto trains in preparation for his upcoming match, he hears Jiraiya speak of "the Fourth Hokage’s legacy". Later on the day before the final rounds, Naruto and Sakura compete with Team 10, with both groups trying to find the secret technique of the "Fourth Hokage's legacy" first so Naruto and Shikamaru could have a better chance of winning in the finals.
Konohamaru was seen wearing his original helmet in this episode, when in fact he was wearing goggles ever since Naruto graduated from the Academy.
This episode has Chōji participating in this adventure, ignoring the original storyline that he was in the hospital for eating too much and did not get out until the following day where he got to the finals in time for Shikamaru's match.