Ok so here is the story

After more than one of the usual symptoms of a bad cat (rattling, awful gas mileage, not to mention that you barely tap it and black soot comes pouring out of the holes) i decided to opt out and replace it myself rather than pay somebody to do it. So the other day i bought a magnaflow direct- converter to replace it with. After almost passing out from WD-40 inhalation i finally got all of the rusty bolts and claps off of both sides of the cat. The issue now is that i can't get the cat from detaching from either the muffler or the downpipe for the life of me. After hours of pulling, kicking, hammering, crying, and more hammering, the thing wouldn't budge at all. I believe that the problem is that the clamps were fastened on there so tight that it kind of crimped the pipes together and that is what is preventing me from pulling the two apart. Are there any suggestions out there as to how i could separate these pipes? I will do all i can to prevent from having to pull out the old sawz all and deal with that. Any input helps thanks!!!

 

i would take out the sawzaw!!! cut it as close are you can to the body of the cat, that way you only have to deal with the little piece of the sleeve that is left on it.

You can cut a lateral cut in the and pull it off.

Thats what i had to do, and i had no rust...

 

I dont see much of a problem just cutting it right in front of the cat if you have to.

Try getting a scewdriver between the two pipes and prying them apart.
the stock cat should be welded in, sounds like yours has been replaced before.

For stuck bolts, use Liquid wrench, PB blaster, or Acetone/ATF. WD40 isnt a penetrating lubricant and doesnt help much in this situation.

 

So i was thinking that if i did end up cutting it then the best way to take the peice of pipe left over would just be to take a grinder and just make a cut right down the middle and pry it off with a screwdriver? If it does come to cutting it that seems like the best way to do it!!!

 

do a horizontal cut on the cat pipe that will allow the inlet to expand if you will and pull off. I did the same thing to get the muffler off with my catback but i dont know what exactly to do to the muffler since you plan to reuse it but you might just do the same thing and just clamp it back on real good and/or have someone weld up the cut on the muffler part when finished.