im so sick of reading all these tabs for this song that are just totally wrong! its not 
individual picking of the strings or doing hammer-ons and pull-offs. WATCH CHIODOS PLAY 
you'll see what im talking about.

anyways, jason hale (chiodos guitarist) plays this song by doing up and down strokes. he 
his "fretting" or left hand to hold down the note and mute the other strings. so thats 
you get the chugging sound.

heres the intro:

|-------------------------------------------------------------|\
|-------------------------------------------------------------| note:these r the muted strings
|-------------------------------------------------------------|/
|------7-5-5--------------------------------------------------|
|-5-5-5------8-8-7-7-7-8-7-7--4h7p4h7p4h7p4h7-----------------|
|-------------------------------------------------------------|

|-------------------------------|
|-------------------------------|
|-------------------------------|
|------7-5-5----5-5-5-7-8-8-7-7-|
|-5-5-5------8-8----------------|
|-------------------------------|

|-----------------------------------------------------------|
|-----------------------------------------------------------|
|-----------------------------------------------------------|
|------7-5-5------------------------------------------------|
|-5-5-5------8-8-7-7-7-8-7-7--4h7p4h7p4h7p4h7---------------|
|-----------------------------------------------------------|

|----------------------------------------------|
|----------------------------------------------|
|----------------------------------------------|
|------7-5-5----5-5-5-7-8-8--------------------|
|-5-5-5------8-8------------0h3p0h3p0h3p0h3----|
|----------------------------------------------|

enjoy.
remember to mute the high strings with your fretting hand to get that chug. i hope you like it.
PEACE!