Exhaust Woes; Signs of a failing Catalytic Converter

[211]

My exhaust has slowly been coming apart.

 

I've got the typical exhaust shield rattle really bad, and based on some searches, there's a whistling noise at high RMP (under load not revving in the driveway) that point toward a bad muffler.

 

I recently got a phone quote from a local muffler shop asking if they could fix the rattle and check on the muffler. The guy "suggested" the cat is probably bad and might be the cause of the rattle. When I asked how much that was he quoted over 400 just for the cat!

I live in the Pacific Northwest where literally every-other-car is a Subaru and this guy clamis to work on lots of them.

 

My question is, how does one know if the cat is bad? No current CEL's, and the only CEL I ever had that was exhaust related was an O2 sensor back at just under 100k miles.

 

2000 OBW manual 145k miles otherwise solid shape; no rust, no salt-road cancer

[MilesFox]

that is what they call an upsell. if the shop does brakes, take up the 'free' inspection so they can tell you that you need new calipers, too.

 

Try to find a ma and pa shop, or stick strictly to the immediate repair without the up-sells.

[Rooster2]

that is what they call an upsell. if the shop does brakes, take up the 'free' inspection so they can tell you that you need new calipers, too.

 

Try to find a ma and pa shop, or stick strictly to the immediate repair without the up-sells.

 

I have both a 98 and 99 OBW's that developed shroud rattles, and later an exhaust leak. In both cases the leak developed with a rust hole at the end of the resonator, which is roughly under the back seat foot wells. I went to a ma and pa muffler shop here in Indy, (Ralph's Muffler) that does the cutting torch, pipe bending, and welding to repair muffler systems. On both cars, I had the resonators replaced with just plain straight pipe. Surprisingly, the exhaust sound is as quiet as stock. Cost out the door was less then $60. I have serious doubts that there is anything wrong with your cat converter. That is something that usually does not break on a Subie.

 

Stay away from the chain muffler stores like Midas, Car X, etc. They are expensive to have work done there. Look in your telephone yellow pages for a ma and pa type family owned muffler shop to get good work done on the cheap.

[Fairtax4me]

When I asked how much that was he quoted over 400 just for the cat!

That's cheap. But it's probably a cheap part too. A new cat from Subaru is anywhere from 6 - 900 depending.

 

A bad cat can rattle. More of a knocking sound than your typical tinny heat shield rattle though. Here's a good example:

[johnceggleston]

that is what they call an upsell.

 

just like: ''would you like fries with that?''

 

or ''for $0.25 more you get twice as much.''

Edited April 6, 2011 by johnceggleston

[211]

This is a ma n' pa shop... well at least it started out as such. They've grown over the years. It's "Martin's Radiator and Exhaust" (for any local surfers). It's certainly not a Midas or anything like that.

 

I like the idea of the straight pipe but when I questioned the price of the cat he said for State (or maybe Federal?) regulations and emmissions they have to repair or replace all exhausts to factory stock-like condition or they could get fined. I assume he was quoting me a price for a OE cat but I can't be certain.

 

I believe the rattle if definitely heat shroud related and not cat. The whistle is annoying but it appears I'm the only one that can hear it.

When I have others driving in my car and I say, "can you hear that?", they're like, "hear what?".

I also feel like power drops off in that RPM range too...

[Rooster2]

This is a ma n' pa shop... well at least it started out as such. They've grown over the years. It's "Martin's Radiator and Exhaust" (for any local surfers). It's certainly not a Midas or anything like that.

 

I like the idea of the straight pipe but when I questioned the price of the cat he said for State (or maybe Federal?) regulations and emmissions they have to repair or replace all exhausts to factory stock-like condition or they could get fined. I assume he was quoting me a price for a OE cat but I can't be certain.

 

I believe the rattle if definitely heat shroud related and not cat. The whistle is annoying but it appears I'm the only one that can hear it.

When I have others driving in my car and I say, "can you hear that?", they're like, "hear what?".

I also feel like power drops off in that RPM range too...

 

 

When I used the term a piece of "straight pipe," I was referring to only the exhaust portion of replacing the resonator unit ONLY. The exhaust shop is thinking you are using the term "straight pipe" as a length of pipe to replace the cat converter, which is unlawful. I hope this clears up the discussion on straight pipe.

 

Much has been written on this forum about silencing rattling muffler shrouds. I determine where mine are rattling, then drive a good size bolt as a wedge between the pipe and the shroud. This has quieted down the buzzy rattly noise on my Outback. If you are ambitious, then use a dremmel tool to cut off the shroud(s). That will stop the noise. The shroud system is only designed to prevent a grass fire should you park in high dry weeds with a hot exhaust system. It is not unlawful to remove the shrouds. I never park in high dry weeds, so I am not worried that my car is missing much of its shrouds.