Hi-Flow Cat

[jetjock]

Couple of comments:

1) All USDM Supras came from the factory with three way converters.

2) A Lex/500 mod will have no effect on an emissions test. If it did something wasn't working or adjusted right.

 

[Poodles]

Metal core cats are supposed to withstand higher temps and more vibration than ceramic.

That's the claims anyway.

I've personally seen an aftermarket ceramic cat melt down and block the exhaust to the point of flowing out the gasket at the flange before the cat. The truck did run pretty rich and I didn't have the knowledge to fix it at the time...

 

[jetjock]

Couple more comments

1) It's true: alumina substrates can handle higher temps but are otherwise more delicate

2) Rich mixtures will not melt substrates because there is little to no O2 in them. What melts cats is lean mixtures combined with high HC

 

[Poodles]

hmmm...

so if there was an air leak into the cat with the car running rich it would meltdown?

it had a probe that went into it, and it didn't seal very well (82' toyota hilux)

 

[jetjock]

Well, we have to define rich. Bottom line is it's HC that does it while "typical" richness won't.

CO (which is used to determine richness) is a result of poor combustion and isn't usually accompanied by excess HC, which is raw unburned fuel/oil. Combining HC with O2 from any source will get things real toasty. That said if he were so rich as to be into rich misfire his HC would have been high. Add the outside O2 source and there you are. On cars that allow it shorting a plug wire can sometimes bring a cat back from the dead. It's a last ditch effort though and not recommend unless you know what you're doing and monitor the cat's temp at all times.

 

[mk3forme]

I just want I quiet car on off racing days. On emmissions in SC, Im just tired of my ears ringing when I get out if my car from. I was looking into cato co. as well.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=CTO-6907&N=700+115&autoview=sku

and vibrant

http://www.horsepowerfreaks.com/price/Toyota/MK3_Supra/Vibrant/Exhaust/Catalytic_Converters

A cat will not offer you much relief. That is not what it is intended for. I was hoping the same and it didnt happen. You need a resonator.