In 2003, the band released their first full-length album, Take This to Your Grave through Fueled By Ramen.Fall Out Boy signed with major label Island Records in 2003 and in 2004 released an acoustic EP and DVD entitled, My Heart Will Always Be the B-Side to My Tongue.Fall Out Boy bandmate Patrick Stump says of Wentz's endeavors: "It scares me sometimes, watching him.The two seconds you're not with that dude he's made 30 decisions that are going to affect our band for the rest of the year." In April 2007, Pete came out with his own signature Squier Precision Bass.
Andy Hurley agreed to drum part-time, but only joined the band full-time later.
His maternal grandfather, Arthur Winston Lewis, served as the U. Ambassador to Sierra Leone; Arthur Winston Lewis' cousin is General Colin Powell.
He considered pursuing a professional career in the sport, but decided that music was a more fulfilling choice; he says that he "always had a magical connection to the ball. Music was more of a challenge and, in the end, felt more interesting." During his first year of high school, he began skipping school regularly and smoking marijuana with friends, but later quit as it was affecting his grades at school.
The band's fifth studio album, Folie à Deux was released on December 13, 2008, and debuted at #8 on the Billboard 200.
The band toured extensively in support of their albums.