Hi All,

New guy here. Just picked up a 1995 850 base model with low miles. Its not perfect, but I'm excited about the new addition.

One thing that I would like to fix right away is the catalytic converter. The previous owner replaced the stock one with a high flow one. He claimed that someone stole it. The problem is that the engine sound DRONES. The first thing my passengers comment on is how loud it is. And I think this drone will drive me crazy if I need to take it on a long drive. The rest of the exhaust is all oem volvo and appears to be in excellent shape. No leaks.

Any recommendations for a replacement, bolt in preferred, but weld in might fit my budget better. Budget, I have one, that is why I wont take the easy route and just purchase an OEM one.

I ask for help on this because there are a number a poorly made exhaust and cat parts available on the market and would like to avoid a $300 or $400 mistake.


Thanks

 

You need to check out what you have. A high flow cat alone shouldn't really change the way your total exhaust sounds unless that guys idea of high flow was to gut the cat before he put it in.
There is a chance the muffler is rusted out internally or you have a leak you don't know about but to have it bother both you and a passenger ???
You should be able to find an auto parts store where someone can make a recommendation of a universal replacement cat, guessing 70-110 ?? It's not going to bolt in unless you take it to a shop and have it "flanged". Most likely it will need to be welded in place but there is a small chance you can clamp it in.
Rockauto $308 for a stock one and that will bolt in.
Autozone $478 pretty much same part
Autozone $76 universal Magnaflow PN 91006
I have a 3" Magnaflow high flow PN 54959 waiting for me to take it in to have a downpipe made.

There is always the salvage yard too.

Photos, stock - universal - high flow

 

I'm pretty confident there are no leaks on the system right now. I can't check it again for a few days because I removed the timing belt and am waiting for my timing belt kit to come in the mail.

I will upload a picture of the one I have. I would say it looks a little like the high flow and the universal. It does not have a heat shield.

I'm new to Volvo's, but on other makes high flow cats are known to make the exhaust sound louder. OEM cats have a lot of baffles and restriction in them which can contribute to muffling sound. That is why I am thinking the cat is the problem. I don't think the inside of my muffler has rusted out because there are no rattles. Is there anything else I can look for?

Also, this is a non turbo car. If that makes any difference.

 

Well,, Catalytic converters do not have any baffles, mufflers do. And you are correct a high flow cat might be a bit louder but I've never had anyone complain about my exhausts noise even when coupled with a less restrictive muffler on a couple different cars and engines. If you have the stock muffler, the really big one in the middle of the car I would be surprised if removing the cat entirely would change the sound much but I'm open to see what someone else has to say on it who's tried a modified set up or two on theirs. After all the cat is just a straight through honeycomb that isn't designed to control or alter the exhaust sound.
And just because you don't hear a rattle in the muffler doesn't mean something inside didn't rust (melt) away.
For you and you passenger both to be bothered by this drone I'd still tend to think it's more likely the muffler failed internally or you have a leak but hey, I've been wrong before.

If you have emissions inspections or might move someplace that does
What he said (Boxpin, below)

 

Before you choose a cat you need to be aware of the smog laws in your state. Case in point, I replaced my cat with a 3" high flow cat. When I went to smog it, it failed because the production numbers on the cat did not match what was recommended for the car. I ended up at the BAR and they said the same thing then gave me a list of two cats that would pass smog in my state. One was OEM and the other was an OEM replacement. That was my choice. Even though I had a brand new cat on the car it was not good enough to pass smog. Not because I failed emissions, it was the numbers on the cat itself.

I live in California.

 

Get a high flow cat then. I am jealous but its sunny here.

( I dont know how this ended up above your post that I was replying to)

 

I'm in Maine. I don't usually speak to highly of our policy makers here, but at least they haven't implemented an emissions program as strict as California.

For my car, a 95, all I need to do is pass a safety inspection and not have any warning lights lit on the dash.

 

He said the previous owner did install a high flow cat but he's concerned that the cat is what is causing excessive noise (drone) in his otherwise stock system.

 

Well to answer that, when I go from cat to no cat then back to cat, etc, there is a definite baffling that the cat provided...so maybe it will help.

 

So has anyone bought a cheap aftermarket cat and been satisfied with their purchase?
I was checking out a few on ebay today. But they are all slightly different.

I suppose the increase in sound wouldn't bother someone who installed a high flow cat because they typically are seeking a sportier sound anyway.

 

There is a difference between a slightly throatier or louder sound and all your passengers commenting on the noise.

 

I got a better look at my exhaust and the muffler section looked a little tired and had been re-welded in a few spots. So, I ordered a new bosal rear exhaust section and installed it today. Sadly, the car is still very noisy. I think that the noise may be related to some leaks near the "ball joint" where the two sections connect together. My clamp is in fine condition, the new exhaust part is obviously in good condition, but the older part of the exhaust is in poor condition.

I was thinking about cutting the joint out and buying a piece of exhaust tube to slide over both sections of the exhaust and clamping with some u-clamps. But, at least on the muffler side there are some bends adjacent to the joint which could make alignment an issue if removed.

Any common solutions for this?

 

Update:

Fixed the leaks by cutting out the "ball joint" and sliding both pieces of the exhaust into a 1 3/4 " ID sleeve and clamped it with some U clamps.

Ultimately, it sounds exactly the same before I started this project, loud and annoying. I should I stuck with my initial instinct on this one and replaced the cat because apparently the muffler section was just fine.

 

Can you post a picture from the cat back, including the new bosal parts. Also, please define what you are hearing...exhaust leak or drone.

 

The muffler is a bosal cat back. It looks like this



The sound I hear is a drone. Its always hard to describe a sound. But when the car is first started in the morning it sounds a little like something that might come from a sub woofer. It is loudest by the exhaust tip.

Here are a couple pictures of the cat. The under carriage looks much worse in the pictures than in person.






Happy Holidays

 

Update:

I finally got around to purchasing a new converter. I bought one that is supposed to bolt in. A Davico off of ebay. Quality was good enough, price was great. Installation was a bit of a hassle because I previously removed the socket flange from the muffler portion. I ended up using a piece of flex pipe between the two.

Anyway, car purrs now. So much quieter.