87 B2 Need cat removal and install advise please.

[Cyrus9586]

So my muffler well was no longer a muffler. It was stock 30 year old muffler (as per my other post I think this whole thing is) and it had a fist sized hole form in it. Tail pipe was rusted out and it wouldn't pass DEQ so I said screw it. I ordered a new system from Macutoparts.com for 320$. It showed up. Looks rough but I cleaned it up nice.

The problem is the old system. 30 years was not kind. A sawzall and 4 hours later I have everything removed BUT the flange that connects the cat to the exhaust. for obvious reason I need to adjoining flange intact so the new cat can bolt on. Problem is 30 years of rust and corrosion and the 3 bolts are fused.

My current plan is to try to get the sawzall between the 2 flanges and just hope I cut the bolts since the old gasket is pretty much rotted to just around the bolts. But there is a problem reaching bolt #3 on top nearest the frame. I don't see any way to easily reach it to do anything to it. I mean even when I get this whole thing out I don't know how I am going to get the new bolt and nut in.

Anyone ran into this and has some pointers? Before I use the heavy method I'm going to give the torch one more go as well since it may burn off some rust to help get the sawzall in if all else fails. Where I cut the old cat off there is about 2-3 inches of pipe left.

Thanks for reading.

 

[adsm08]

This is not a fun job, as you already seem to know.

Unless they are already pulling apart I wouldn't try the sawzall between the flanges. I have tried it and mostly turned into a waste of time. It didn't get my exhaust apart and it did damaged the flanges.

I would just try burning the nuts off if you have a torch. I don't go after exhaust without the torch anymore.

As for getting it back together, still not fun. I usually stick bolt #3 in first, so that the cat can be swung down out of it's normal position for better access to get it started. Then swing it up and get the other bolts in, tighten the outer ones first, then you (well me) can get one arm up over the top of the cat to get a wrench on the back side and use an extension and swivel to get a socket on the front side. It can be done with hand tools but power is your friend here.

 

[Cyrus9586]

There is enough room to get a saw blade in between them but ill go for the torch method and see how it fairs. I'll also take your advice on the bolts as well. Pray for me for this may be what makes me throw a wrench this week lol.

 

[adsm08]

If your flanges are pulled apart then the saw might just work. I tried it on one where the bolts were rusted so badly that they looked more like rivets and ended up damaging both flanges badly.

 

[JerryC]

I've got a leak between the manifold and the y-pipe.

The big "IF" - if the bolts at the manifold come out it looks like an easy job and then just bolt in all new stuff. "IF" they break off...

I'm with adsm, torch if I had one.

I'm taking mine to an exhaust shop, over the phone quote ~$600 for all new from the manifolds back. Whether or not they'll stick to that once they see it I do not know.

While you're there you might want to put in a new 02 sensor.

 

[alwaysFlOoReD]

This might be one time I paid a pro to disconnect the exhaust. I would still install it myself.

 

[adsm08]

I'm taking mine to an exhaust shop, over the phone quote ~$600 for all new from the manifolds back. Whether or not they'll stick to that once they see it I do not know.

While you're there you might want to put in a new 02 sensor.

That's not a bad price.

Also, you make a very good point. The oxygen sensor will never be more easily accessible than while the cat is out.

 

[Cyrus9586]

Its only 40$ for a new o2 sensor but buying the new exhaust set up broke me for the month. I'm about to go in with the torch now and see what comes of it. I'll post an update either when the old stuff is off and IF I get defeated.

 

[alwaysFlOoReD]

Good luck!

 

[Cyrus9586]

I have been defeated... sorta...

so I ground off one bolt. Snapped the nut off the other but it was clean but the top one I couldnt reach with a ratchet and cheater bar to snap off. I ended up cutting the exhaust flange off. While doing so the third bolt vibrated loose...But only after I had cut 1 pipe and was 75% of the way through the other.

I am using exhaust connectors with high temp 2400 degree epoxy. I just sat down to shower and first wanted to give this update. Thanks for all the advise I just didn't have the luck with me this time but this connector thing was told to me by a friend who has done this to many of his cars so I have a good feeling about this.

 

[Cyrus9586]

New update. So with all the issues I decided to install the tail pipe and muffler and test fit the cat in place..Don't order from Macautoparts.com the flange to connect the muffler is rotated out of alignment. Also even before cutting off the exhaust connection flange it would have been too short to fit properly.

 

[Cyrus9586]

Okay final post for this thread. Its in. Took a couple pipe fittings 3 brackets a lot of swearing and I will need to get some JB steelstick to patch the couple minor leaks it has but its in. Thanks for all the advise and help on this.