i need to know how to get the top back bolt on the precat off. all the other bolt came out easy as hell, but i cant figure out a way to get it off.

 

will it not budge ,,or you cant get spanner on it ( if it wont budge try soaking it in WD40 or nut buster)

 

What's a pre-cat

 

i got it off, and finished the install. everything went super smooth. no broke studs and the bolts came off with hardly no efort at all. didnt even use pb blaster on two of them. the downpipe slid in perfect too. really happy with it.