Im putting an exhaust in my ls and I need to cut some of the bolts out
the three that connect the cat to the cat back they are rusted to death
and even with a breaker bar will not even break off
my question is is the rear flange on the cat threaded?
If i cut the nuts off will that funny looking flat washer like end piece still be threaded into the flange or will it just fall out like the spring bolts closer to the muffler?
sorry for the lame question and length and Thank you.

 

the flange isnt threaded, if you noticed there are nuts on the other side. good luck drilling the bolts out after you break them, i busted about 4 drill bits trying to drill those suckers out. try spraying some pb blaster on them and let them sit over night and try again the next day. it might not work but its worth a try.

 

thanks for the reply, I forgot to mention that i have sprayed the bolts down with wd-40 for two days prior to today and they still wont work with me
I decided to cut them out because my new exhaust is laughing at me from the garage h:
so i'm gonna give it a shot with the cutting and drilling if I fail again I'll suck it up and pay someone to finish. The only loss will be pride and money but I'll have my exhaust

 

yea you're just going to have to drill them out if they break, no big deal. it will just give you an excuse to buy new bolts.

 

i forgot....what size are the bolts connecting the bpipe and cat?

 

Aren't they 13 mm bolts, but anyways what you need is to get your hands on a neumatic gun, when i changed mine i just cut it in between the muffler and resonator to take care of the back end of the exhuast, but i used wd-40 and pertrolium oil to break the rust at the catalytic converter and after an hour or so of trying to break the bolts by hand i remember my neighbor had a neumatic gun so i grabbed my air compressor and had the nuts off with no problem at all.