Rattling catalytic converter

oldapeman

Rookie My A$$!
So your only problem is "cosmetic noise"?

I can relate, however I can't think of a solution other than replacing the cats. The element inside the cat has crumbled to allow the whole piece or a fragment to rattle against the enclosure. I think they are built differently now so this doesn't happen on newer cats.

Since I have access to shop equipment, I might cut it open and wrap the honeycomb with steel wool to stop the rattle, but why when it would probably benefit from newer better cats anyway.

Yes, noise only, no performance problems or trouble lights. For now.
 

aram

Well-known member
Yes, noise only, no performance problems or trouble lights. For now.

If it were mine, I'd unbolt it and dump the loose pieces out and then weld it back up. If it looked real bad in there, I'd get a universal replacement on everyone's favorite auction site for $100 or so and weld the stock heat shield on top and give it time to rust up to look like the stock one.
 

brichter

Spun out freakshow
Man, the craziness I read on here sometimes... :rolleyes

OP, I'm pretty sure there's a cat that is listed as a 49 state replacement that's also approved for use in CA on your car (most likely listed for the same or a different vehicle), as the aftermarket cats are, in virtually every case, manufactured to fit many different vehicle models with a single part number. It would be cost-prohibitive for an aftermarket manufacturer to produce a separate part for each and every car ever made that was equipped with a converter. If the same model listed for your 49 state car is also approved for use on a vehicle that is 50 state or CA approved, it will have an EO number, and that EO number will have a listing in the ARB database that states ALL the cars it is approved for, not just the 50 state or CA emissions cars. If this is the case, you're good to go.

<edit>
So I got ambitious and did a few minutes of research. :nerd

According to the EO I've attached here (D-182-48), you're looking for a Walker 81807. AutoZone lists this on their website for $105.99 each. Cross-checking the number to the application on their site verifies it is the correct one for your car.

I suggest you either look for a muffler shop that will install your customer-supplied parts (this shouldn't be a problem if you bring the EO with you), or find a shop that sells Walker cats and have them do the job. I think you'll be out the door for a lot less than a grand for both cats, either way you go. :cool

I don't blame you for wanting to keep the W210, they drive well and last a long time (well, except for trying to keep those huge headlight lenses from clouding up due to UV light from the sun!). :party

Damn, the file is too big to upload here, so here's the link instead. :)
http://arb.ca.gov/msprog/aftermkt/devices/eo/D-182-48.pdf
 
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angelsndevils

gas burning o-zone killer
Pull half way in a inclined driveway so the center of the car is over the ditch so it's got a little extra room. Slide under there and bang on the exaust (after it cools) with the heal of your hand. If the rattle is coming from inside the exaust then you're cat is breaking down. If not it's just the heat shield has come loose and will need to be re tack welded. I've seen this hundreds of times. It takes longer to get the car on the lift than the actual tack welding.
 

Hubbard 0

Midwesterner
Or you could use a screwdriver with the handle up to your ear. I thought my rattling cat was rod knock at first.
 

oldapeman

Rookie My A$$!
brichter, Thanks for your research. I am going to follow up with that alternative. It looks like the best solution, and the least cost.
 

brichter

Spun out freakshow
Glad to help. Hopefully you can keep it on the road for another couple hundred thou... :thumbup
 

oldapeman

Rookie My A$$!
Here is an update for anyone who is interested. brichter put me on to the Walker brand CARB approved cats. Further research reveals that there are 4 cats on my car, and the ones making noise are the two rear cats. These are Walker part number 81652, which I can get online for about $130 each. That is great news. The bad news is that they may need to be welded in, and I do not have that capacity. So, right now I am looking for a competent welder willing to do the job. It is stainless steel. If anyone has a recommendation, let me know.

I did take it in to a local muffler shop with a good reputation, but they wanted to charge full retail for the two cats ($450 each), plus installation, for a total of over $1100. Screw that.

I am going to order the cats online at a third of retail, and figure out how to get them mounted. If I had access to a lift it would be easier, and I would just do some cutting and clamping, maybe with some adapters.
 

brichter

Spun out freakshow
Glad to be of assistance, hopefully you can find a shop to put them on.

I'm ashamed at the behavior of that shop. Installing the cats for you, while not allowing them to make 200%+ (125%+ if they went to the local AutoZone and paid retail for it at $195) profit on the part :)wow), was still not something that would have lost them money, unless they're just so busy that they never have an empty lift.

I'm in the South Bay so wouldn't know where to begin to find a good shop in Berkeley, other than Yelp: http://www.yelp.com/search?find_desc=muffler+shops&find_loc=Berkeley%2C+CA
 
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