All Killer No Filler and Does This Look Infected? (2001-2003)
Sum 41's first full-length album, All Killer No Filler, was released on May 8, 2001. The first single released was "Fat Lip", which became a huge hit during the summer, becoming the #1 rock song in the US as well as many other countries around the world. Performances on the Warped Tour during the year further increased the popularity of the band.
Two other singles were released. They were "In Too Deep", which had a comedy video of the band in a diving competition, and "Motivation", a simplistic video of the band playing in a classic garage band theme. The band toured for much of the year, playing 300 shows in 2001, including opening for Blink-182 on tour before returning to the studio to record another CD.
On November 26, 2002, Sum 41 released their second full-length album, Does This Look Infected?. Sum 41 altered their style slightly, bringing in a heavier style, while keeping the smooth harmonies they had become known for. “We don't want to make another record that sounds like the last record,” declares Whibley. “I hate when bands repeat albums.”  The first single released was "Still Waiting", the video of which had them mocking "new-garage" retro-rock under the name of "The Sums" and was a parody of one of The Strokes' videos.
The band followed up the release of "Still Waiting", with "The Hell Song", a unique video of which had the band using dolls with their pictures on them and others, such as Ozzy Osbourne and Pamela Anderson. Their next single,"Over My Head (Better Off Dead)", had a video released exclusively in Canada and on their website, featuring live shots of the band. The video was also on their live DVD, Sake Bombs And Happy Endings (2003), as a bonus feature. It has also received limited airing on various music television stations in the USA and UK.
After extensive touring in support of the album, Iggy Pop recruited Sum 41 for his new album, Skull Ring. Deryck co-wrote the first single from the album, "Little Know It All", and joined Iggy on The Late Show with David Letterman to promote the song. Iggy said he chose Sum 41