School me on exhaust work

[ovilla]

I've decided to put my 02 Honda Odyssey on my Bendpak HD-9 and swap out the exhaust. On the Ody, it's a one piece muffler deal from the cat all the way to the muffler tip. Anyway, my van has 167K on it now and the original exhaust nuts/bolts that attach the cat to the muffler look like caked on mud (thanks to the salt they spread on our roads each year). I've already used a wire brush on things and have been assured that there's nothing meaningful left. Looks like a clay/putty bolt, nut, and muffler pipe flange.

How do the muffler shops remove the old exhaust parts? Should I grind these off, use an air hammer, or cut them off with my reciprocating saw? Also, is there any trick to removing what's left of the bolts coming out of the cat flange without damaging the cat?

Thanks for all of your help on this one. I just refuse to take this to a shop. Plus, I don't own an air hammer yet and think I might end up with one by the time this is done.

 

[35mastr]

A Torch is the best way. Fast and easy. That is how I have always done it.
But any of the methods that you mentioned will work. But lot more time consuming.

 

[xcgates]

I ripped of the muffler of my Subaru in a sudden, violent, and unexpected off-road excursion, then fixed it by having a friend weld on some new pipe.

It took some time and patience, but I used a HF angle grinder (electric) and cut/ground away anything that was holding on the old pieces of exhaust. Oh, and get new bolts, as you will not be able to salvage the old ones, and they aren't worth it, anyways.

As far as time invested in it, it was just a couple hours. Spread out over a long weekend, but still just a bit of time.

 

[nehog]

Sawzall is what I usually use, less risk of a fire or damage that a torch with modern cars and vans. Take seconds with a metal blade to go through a tail pipe.

I love my Sawzall, both of them!

 

[Dewaynep]

I'll second the Sawzall. They work great and don't have any chance of starting a fire. As for the bolts on the Cat, is it a flange with 2 or 3 bolts sticking out of it or a normal pinch connection with a muffler clamp? If it is a flange, cut the studs/bolts off and install new bolts. If it is studs you'll have to cut them off flush and drill the rest out or, if they are pressed in, you can just hammer them out.

 

[ovilla]

I'll second the Sawzall. They work great and don't have any chance of starting a fire. As for the bolts on the Cat, is it a flange with 2 or 3 bolts sticking out of it or a normal pinch connection with a muffler clamp? If it is a flange, cut the studs/bolts off and install new bolts. If it is studs you'll have to cut them off flush and drill the rest out or, if they are pressed in, you can just hammer them out.

I can't tell since everything is so rusted together but I just checked he Honda parts diagram and it appears to be 3 bolts that go in from the back of the cat flange and then bolt on to the muffler flange, with some type of gasket/washer between the cat and muffler mating flanges.

You won't believe how long the one piece unit is (which consists of a pipe, resonator, more pipe, and final muffler ). Must be a good 7-8' long. Anyway, I'm going to order it today, so no turning back now.

 

[csp]

Lots of rusty bolt/nut removal tips in this thread: http://www.garagejournal.com/forum/showthread.php?t=77358

 

[graffix000]

Another vote for the sawzall. That is how I removed the exhaust on my Jeep GC that had 210k miles on it. Worked like a charm and was able to salvage the cat.

 

[red baron]

sawzall or a torch

 

[moserjj]

I worked in a muffler shop for a few years and I don't think we ever removed old exhaust with anything other than a torch. You'll fight those rusty bolts on that flange for a long time with any other method. You could cut off the pipe with a saw but you'll need to get that flange apart and a torch is easily the fastest method. Since you have a hoist, I'd buy yourself a small torch set. Otherwise a muffler shop can throw that exhaust on in no time at all.

 

[barney rubble]

Re: School me on exhaust work

It *****.

I hate doing it and have a fully functual muffler shop at my disposal 24-7.

 

[ovilla]

The story gets even more interesting.

I thought for sure that my van needed a new exhaust since it's been making a weird groaning sound out the back. Anyway, I put it on the lift to really inspect it and though a bit rusty there was nothing visibly wrong with the exhaust itself. Okay, I'm thinking that maybe it's an internal issue with the muffler. Since I don't drive the van that often, I went ahead and parked it in front of a strip mall (close to the front store windows) and revved it. Guess what - sounded completely normal.

Then tonight, I had to go pick up something from a nearby town. We're talking about 30+ miles of winding roads. I turn everything off and really start listening closely for noises. That's when I figured it out. As I was making a long sweeping right turn the noise in the van was changing. Then when I was making a left turn it would get louder.

Guess what it is yet?


Wheel bearing!!!

Thought it was the exhaust since it was resonating so loudly up front but I'm almost positive it's a wheel bearing now. As I was coming home on the country road, I put the ****** in N and turned everything off - just coasting at 50 down the straight road. The noise was still there, even with the motor off. I'll know for sure tomorrow after I put it up on the lift again and spin the rear tires. Anyway, just wanted to keep everyone up to date here.

P.S. Thanks for the exhaust tips. I'm sure that'll be next on my list.

 

[dirttracker18]

Torch is by far the easiest method. the sawzall is a little safer if you can get it in there but there is often limited room. As stated already the exhaust shops use the torch for speed, quick and dirty. get new gaskets as the old ones will likely not be any good, plus they are cheap.