Muffler Replacement

looks like you got it figured out. but, I would soak the old hardware with penetrating oil every day until I was ready to do the job, so that hopefully you don't have to break the old hardware, and might be able to re-use it since its got little springs on the special oem bolts iirc. I don't remember if the nuts are welded to the flange; if they are then you definitely don't want to damage the oem hardware, nor can you replace them with some crap from home depot.

 

Tightening torque on the bolts w/compression springs is 32 ft.-lb. Two needed where the catalytic converter bolts to the exhaust manifold; and two which attach the rear of the catalytic converter assembly to the muffler at the rear of the car. It sounds like you are changing only the muffler, not the long pipe with the two catalytic converters and resonator. I also recommend that you use the correct hardware only. Also, you should take a good look at the rubber hanger holding the muffler to the body, and it might be easier to cut the old rubber hanger off and use a new rubber hanger when installing the replacement muffler, rather than try to reuse the original rubber hanger.

 

Any muffler shop will do that in 15 minutes for $40.

 

Mufflers suck. Evey-thing is rusted on tight. You usually need a torch to get most of it off. Muffler shop will cut that pos off in about 29 seconds and weld up a new one. I wouldn't put on a used muffler just go buy an aftermarket muffler. If you have to do it yourself make sure you wear eye protection and have a good set of leather gloves. Its the only thing I won't diy on a car....for good reason your about to learn.

 

That looks like an aftermarket muffler, which being in the rust belt, explains your situation. The OEM mufflers, actually the whole system, are made from some variety of stainless steel. Therefore, your replacement from a southern vehicle with take-off parts is an excellent idea!

 

I think the nuts are made on the flange. and that's why you need to spray penetrating oil on the nuts every day for a week or more so that hopefully, you won't need an acetylene torch to heat them up so you don't break the old bolts off and have to drill and tap the nuts. pb blaster is a very good choice for penetrating oil, but even wd40 is better than nothing.

 

I think map gas burns hot enough to make the nuts glow if the bolts are totally seized. I bet there's youtube vids on how to remove seized nuts with a torch.