A few weeks back when I had an oil-change done after buying my used 99 Eldorado the mechanic said the tailpipe and the catalyst converted looked rusted and that I might have to replace these.

I'll have to get some quotes but what would be a reasonable price to expect?

 

The catalytic converter, pipes, and mufflers on the 99 Eldos are stainless steel. I've never heard of these rusting. Take a look yourself before you decide to replace them. If they are rusty, somebody replaced them with aftermarket parts.

 

WOW, i see these rusted up every day. And thats here in sunny FL.
Many times the torch it the only way to get the nuts off the converter.

Sorry, not SS.

I know a complete cat back systems with mufflers and tips is a little under $1000.

 

FLCaddytech – I'm sure that you do see rusted-out exhaust systems all the time. If you are a tech at a Cadillac dealer, you will see typically 10 cars a day. Eventually you will see everything. My car is a 1997 ETC and all the stainless steel is fine -- and original. If the current or previous owner has replaced the exhaust system with a cheaper one, then it will eventually rust out. I would hope that the ones you see rusted out all the time fall into that category.

Eldo99er -- My advice stands: look at the exhaust system yourself before you replace it. A mirror and a flashlight are all you need to do it from a kneel.

If you do replace it, you probably should go with another stainless steel system. A cheap system (galvanized piping and aluminized muffler) will be good for a year or two but you can count on those rusting up eventually. The exhaust system is a safety item as well as just something that quiets the car and makes it legal. Because of the durability and cost of stainless steel piping, you might consider replacing only the parts that need it, which could be only mounting hardware. The $1K quoted by FLCaddytech isn't bad for an all-stainless exahust system.

 

I wouldn't do anything until it starts leaking. You'll be able to hear it. It it's just surface rust it could last for years.

One thing that rusts exhaust systems out here in Colorado is short drives, say if you live only a mile from work. It allows condensation to build in the mufflers, but not get hot enough to dry it out. So the water sits in the bottom of pipes/mufflers and rusts them from the inside out.

I would run it until something rusts through.

 

I recently bought an 02 ETC from Niagara Falls, NY and believe be the mufflers are cooroding from the harsh winters up there and the salt they useon their roads. There is also a lot of coorosion at the panel seams, screws, nuts, etc. I have coated everything with a metal protector hoping to slow it's advance, everything except the mufflers. Yes stainelss does coorode.