Need 355 Cats

Hi Folks,

I'm looking for a set of OEM catalytic converters for my 1999 355. Slightly used is fine; for example, if they were removed by someone replacing them with an aftermarket set-up, but they need to be able to pass California's smog requirements. Any leads would be most helpful. Thanks!

Doug

 

You should get the SoCal guys to chime in here as many have had exactly the experience you are having. Trojanfan recored his OEM cats through fabspeed and passed for example.

I'm on the other side of the country so only speak tangentially on this from a CA perspective.

Hopefully others will chime in.

 

If you get the 1999 model year cats, they are metallic, versus ceramic and much more durable and won't crumble like the earlier ceramic ones. My experience with recoring was less than satisfactory (metallic cores). They worked for about a year, then threw "low catalyst efficiency" codes. Extenders eliminated the problem, but that just means you will never know if the cat is actually working or not, cause the secondary O2 sensor is out of the path of the exhaust. I found some new, 1999 oem metallic catalysts on Ebay for a song and never looked back.

 

Interesting because I had to change my 99 cats for hyperflows in 2007

 

I believe metallic core were used near the end of production. I don't think it was exclusive that all 99's had them.

 

What are some of the last 99 build dates then

 

No idea, Grant. Dave Helms was the first to educate me regarding OEM metallic cores. I was hoping my 98 would have them but they were ceramic.

 

Are you looking to borrow or buy?

 

You do not need OEM cats to pass smog
CARB approved cats will be fine as long as you have the certificate for them
Anything over 7 years old or 70000 miles can use aftermarket CARB approved cats.
I build my own as got tired of the small inefficient one's offered for our aftermarket. Sorry I dont sell them just do it as a hobby.


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Another reason 95s are bets.

 

How is a 95 going to be better in an area that does sniff testing?

 

Seth - I'm interested in buying.

Doug

 

Seth - I'm looking to buy.

Doug

 

How do you build them?
I like to do it myself for my 92 348 tbspeciale.
thanks in advance.

 

Basically a box of stainless tubing, flanges and a cat start welding
Need to get a machine shop to cut flanges is about the hardest part rest is just welding.

 

Mine was in March of '99.

Doug

 

Thanks for all the good input. I did indeed look into the "universal" cats as a replacement, but my mechanic said nothing fits without extensive rebuilding/configuration. He was then fortunate to find a set of used cats that come with a six-month warranty from the seller. So, I should be able to get the vehicle smogged successfully once installed and then have a couple of years to figure out if some universal ones that readily fit become available.

Doug

 

I have a set if your not in a hurry. Pm sent.

Sent from my SM-N920V using Tapatalk

 

I'm about to Fab some test pipes for my 95 355.

 

I was hoping all the replacement OEM cats would now be metallic, but I asked the folks at Eurospares and they believe they are still ceramic. Can anyone confirm this?

Thanks

 

Just to chime in, I had my factory cats re-cored by Fab Speed 3+ years ago and no issues. I have them tested each year and they are reading very clean.

 

Thanks, Peter, but I don't understand Fabspeed's pricing. According to their website, they're asking Australian $3,943.82 to recore my old cats with HJS trimetallic cores (and I'm assuming postage to/from the USA would be additional). If all the OEM ones now have metallic cores, it would be cheaper for me to buy new OEM ones from the UK.

Of course, the Fabspeed recore material may be better quality, freer flowing, etc, but I don't know if the difference would be noticeable to me in the short or long term.

 

And you'd have to pay tax on the way in too! Not a viable option IMO.

I have a spare set of OEM gutted cats that I will one day get around to recoring locally.

 

Do you know of anyone Sydney (or Australia) which does this, Elliot? (and makes the welded seams look original)?

 

Doug,

In my opinion, your best bet is to find a set to re-core. I just sold my set (1998 Ceramic) on Ebay to a someone in California who plans to re-core them. They started to throw codes and were basically internally falling apart. I replaced them with Fabspeed cats and passed the emissions with no problems. Fabspeed uses the same metallic core that I have when they re-core the original units.