I was gutting out my old OEM catalytic converter today. I noticed there are two seperated metallic substrate, honeycomb parts in OEM catalytic converter. It's not one big piece as I though, but instead they're two seperated pieces. I labeled the areas as 1, 2 ,3



Area 1: This part, common knowledge, is reponsible for triggering the CEL since it's infront of the O2 sensor. It's the first metallic substrate, honeycomb part.
Area 2: This is the hollowed or empty part of the catalytic converter.
Area 3: This is the second metallic substrate, honeycomb part that is can be removed or gutted and will not trigger the CEL since it's behind the O2 sensor.

If you removed or gutted, the Secondary metallic substrate cores, Area 3, you would basically have something similar to the Berk Technology High Flow Cat. It would definately take away some of the restrictions and give you more exhaust flow. I am not sure if it would pass emissions test this way, but you should not have the testpipe smell

Open for discussions or flames...

 

You are sooooooo in troooooouuuuble. Mmmmmmmm, I'm telllllllliiiiinnn.

Anyway, was this a spare CAT you are playing with? I wonder how it would do on an emissions test if you didn't even tell them about it.

Good luck and put on your flame retardant suit......

-Hockey

 

Good catch! This design is weird, more like a ULEV failsafe?

But ignoring the obvious Federal law violation, I don't think the gains would be worth the effort with any of the above. These aren't those horrible bed style cats, these area pretty clean design.

 

We need a volunteer!

 

Interesting, but I wouldnt do it unless I have a spare cat to play with.

 

Done. I have an extra cat that I got off a wrecked S2000 that I was going to make into a ghetto test pipe to pass road side visuals but when I started to gut it I noticed the same thing. I decided to leave the first layer in and just pull out the second.

Afterwards I went to my cousins smog shop and tested it. It came back as just barely failing. And this is on new plugs and filters, so it would prolly be a little worse on a car with a not so fresh tuneup.

I think though if you retuned with a piggy back to lean out a bit it would fly!

 

Nice goin'. Thats the nice thing about this site. There are enough of us that SOMEBODY has tried it at one point or another. It is just a matter of whether they are watching at the time ot not.

-Hockey

 

So unless your state/county tests up the tail pipe for smog, you'd be fine right? Most states and counties just read the car computer for emissions now, right?

 

I know MA does. Hell as they don't smell it or look under your car I've known people to pass with test pipes just because of the anti-foulers.

If the OBDII port says it's good, thats enough for a MA sticker.