how do u know when u know a pedal for a song and it doesnt say on the tab
you can hear it

07 Fender American Deluxe Strat
07 Fender Custom Telecaster
09 Seymour Duncan Pickup Booster
09 Fulltone OCD V.4
10 Ibanez WH-10 V.2
09 Splawn SuperStock
10 Jet City JCA-20
97 Fender Hot Rod Deluxe

Yeh the SICK! bit sounds a bit stupid.

wow you two guys above are really helpful

Generally I just try and figure out what effect it is. You can post here on the forums if you know what song it is, sometimes people look for the specific pedal the band uses or the guitar player uses, which can usually be found on the bands website or the bands forum.
I honestly can't think of more than just listening for it. You may get better responses in Electric Guitar or Guitar Gear and Accessories. Apart from that, I really can't help you.