My '05 needs a cat, the one it came with was gutted. When I search the net I come up with so much stuff I don't know how to weed out the junk from the good stuff. Anyone have any recent experience with this, or at least know how to tell who or what is reputable?

 

It would say CARB Compliant.
https://www.exhaustking.com/ny-ca-carb-compliant

 

For CARB compliance, you probably have to go with OEM.

 

There's at least one aftermarket option that will get you past the test. See conversation here. No idea if the new part # means improved reliability vs. other aftermarket cats.

https://www.rx8club.com/west-rx-8-fo...entura-267841/

If you get the Magnaflow, please take and post pics of the EO #. Curious to see what markings these carry.

 

My combo(which SteveDallas inspired) works, but it's just as pricey as OEM.

It really depends on how strict your emission test is. Lots of cats can make the P0420 go away, but if they look for more than that, it may be harder to hide.

 

As I understand it, CARB requires OEM or a part with a specific exemption/approval. This isn't just an OBD or sniffer test. If the part isn't OEM, it needs to have a sticker saying that it's CARB compliant.

 

If you want to be truly CA legal, I know of 2 options: OEM or Magnaflow CARB compliant. The Magnaflow cat will not last long, so if you go that route, install it for inspection, then swap back to the gutted one for the rest of the year. If you go OEM, you can buy used, but be sure to inspect the honeycomb to make sure it is completely clear (both front and rear cartridges).

 

It would need to be a metal tag or something more durable than a sticker.
Documentation maybe?

 

IIRC, the sticker goes under the hood.

 

That makes sense.
Derp.
0_o

 

good news is they don't do the sniffer test anymore in CA sooo.... hypothetically speaking... if you just throw any cat on there it should be enough to pass the OBD II test.
assuming your tech doesn't crawl under there looking for an OEM cat.

 

If they fail it, do they give you like 30 days to fix it?

 

yeah, I think you get up to 60 days to correct and re-test.

 

Thanks for all the help. Looks like the Magnaflow will work. Cheapest I found was $908 from Summit. Others are almost $50 more. A lot of money, but I'm not surprised, just gotta pay what I gotta pay.

I've heard that it's illegal to sell used cats, at least in CA. Anyone know if this is so?

 

Idk, Jedi might.

 

I believe there's some obscure rule about that but nobody actually enforces it. I see them for sale all the time and you can even get them at junk yards.

 

Follow up. I did get the Magnaflow 546150, and I did pass smog. Now, I'm nervous about how durable these are, I've seen a lot of talk about how aftermarket cats fail really easily, especially if you autocross or do track days. I have a track day Tuesday, and I'm thinking of swapping in the stock, gutted cat, I'd hate to have my nearly $1000 brand new cat fail before I've even put 100 miles on it. Anyone have any long term experience with an aftermarket cat? How'd it work out?

 

I think you are better off with the gutted pipe then.

I have a cat works for AutoX(see my signature), and there is someone else on here that also uses the same setup and can do track days on it. It's pretty expensive, though, and hard to get nowadays(you have to import one from Germany).

 

I have seen aftermarket cats fail during a single track day in RX-8s. Definitely put your gutted cat back on before taking the car to the track.

[EDIT] Food for thought: Your Magnaflow cat is rated for 1200F EGT. I measure upwards of 1800F sustained at my rear O2 sensor on track days.