Yes I know you can ease the effort of loosening bolt with WD-40. My question is, is it safe to spray that sfuff on the bolts that connect the exhaust piping to the cat, without the piping, bolts, and stuff catching on fire? I have a Mugen coming in a few days and I want to install it myself. Any tips on installation, I heard that the bolts are B!tch.

Yep it's a Mugen

 

Yes it's safe, no it's not going to catch on fire.

 

get some liquid wrench

 

PB Blaster works even better if you can find some.

 

Use a cheater bar. Increase your leverage and it makes the job hella easy.