Prophecy0

My fiance's Civic (94 EX) developed a huge hole in the muffler and the entire exhaust pipe was rusted over and riddled with holes, so I bought a cheap cat-back exhaust off of eBay to replace the stock one. I know it'll probably sound like ***, but she just needs the car to get her back and forth from college.

I don't know too much about working on cars, but I figured I knew plenty to do a simple bolt-on replacement like this. I didn't have much trouble until I got to where the exhaust pipe bolts to the catalytic converter. The nuts on the bolts there simply would not budge, no matter how much wd-40 I sprayed on them to try and loosen them up. My cousin let my borrow his grinder so I could just grind them down and then knock the bolts out with a hammer.

I was able to grind each bolt down and get the exhaust off. I breathed a sigh of relief then grabbed my hammer to knock the bolts on out... only they won't budge. At this point I'm not sure what else to try. A friend of mine seems to think that the head of the bolts might be welded to the cat. I'm praying this isn't the case.

So, does anyone here have any suggestions? The only thing I know to do is remove the cat so I can grind the heads of the bolts down then hope they just fall out. I've included some crappy pictures to give a visual on what I'm talking about.






Modified by Prophecy0 at 10:52 PM 2/17/2007

ChadB

You would better off to make a cat-back system with v-band claps and make sure it 304SS.

Padawan

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Prophecy0 &raquo;</TD></TR><TR><TD CLASS="quote">A friend of mine seems to think that the head of the bolts might be welded to the cat. I'm praying this isn't the case.</TD></TR></TABLE>

Unfortunately, he's correct.

As you stated, you can try removing the cat, drilling/grinding out the bolts, and then replacing them with the standard variety from your local hardware store.

97CTR

I just happened to replace a friends exhuast yesterday and had to deal with the same problem. The stock cats "bolts" are really studs that go through the cat flange and are threaded on the end to tighten down with the nuts. You will have to take the cat off and grind down both sides of the stud all the way down to the flange. You won't have to drill them out, you can punch them through with a hammer and punch or whatever will work for you. They may not come out easily but the will punch through.

After grinding try cooling the metal as quickly as possible to help punching out the studs.

Prophecy0

Thanks for the responses. I'll try removing the cat and grinding down the ends of the studs.

Prophecy0

Update: I was able to knock out one of the studs with a hammer after taking the cat off. The other two weren't budging, so I ground down the head of one of the studs all the way to the flange. After using lots of wd-40 and pounding the crap out of it with a hammer it still won't come out.

This is driving me crazy at this point. The only thing I know to do now is to drill out the two remaining studs. I'm heading to Home-Depot now to get whatever bit I need to drill out the studs.