burning a cat :)

[arodg25]

theres something wrong with my car. i first got a new cat installed last september then it started rattling in december or january, so i when back to the muffler shop and the guy said it was cooked, anyway he replaced it and now the new one is rattling so for some reason my engine is cooking these things. i have a b16a and installed 2 new O2 sensors last january, any ideas what i should check?

[turtlecrxsi]

I bet that smells bad and probably taste awful. Then again I would never cook or eat a cat... ew gross!

In all seriousness, catalytic converters are just metal tubes with metal in them. The temperature inside an exhaust system is hot so naturally it's going to look toasted after a year. If you don't have emissions just get a high flow cat or resonator installed.

[kinfolkdebo]

ya I would just take the damn thing out.

[FrodoGT]

Well, the purpose of the cat is to burn off excess fuel that hasn't burnt in the engine...and what can happen is far too much fuel will heat the cat up immensely, if your running really rich the damn thing will glow like a cherry!

[CRXperiment]

Yeah, like Frodo said, you could be running rich. Adjust the ignition timing back to spec (16 degrees) and maybe change your plugs.

[Hybrid1990crx]

Originally Posted by turtlecrxsi

I bet that smells bad and probably taste awful. Then again I would never cook or eat a cat... ew gross!

In all seriousness, catalytic converters are just metal tubes with metal in them. The temperature inside an exhaust system is hot so naturally it's going to look toasted after a year. If you don't have emissions just get a high flow cat or resonator installed.

wow dude if thats all you think a cat is you really need to do some learning about them.

[turtlecrxsi]

Originally Posted by wikipedia

The catalytic converter consists of several components:

The core, or substrate. In modern catalytic converters, this is most often a ceramic honeycomb, however stainless steel foil honeycombs are also used. The purpose of the core is to "support the catalyst" and therefore it is often called a "catalyst support". The ceramic substrate was invented by Rodney Bagley, Irwin Lachman and Ronald Lewis at Corning Glass for which they were inducted into the National Inventors Hall of Fame in 2002.
The washcoat. In an effort to make converters more efficient, a washcoat is utilized, most often a mixture of silicon and aluminium. The washcoat, when added to the core, forms a rough, irregular surface which has a far greater surface area than the flat core surfaces, which is desirable to give the converter core a larger surface area, and therefore more places for active precious metal sites. The catalyst is added to the washcoat (in suspension) before application to the core.
The catalyst itself is most often a precious metal. Platinum is the most active catalyst and is widely used. However, it is not suitable for all applications because of unwanted additional reactions and/or cost. Palladium and rhodium are two other precious metals that are used. Platinum and rhodium are used as a reduction catalyst, while platinum and palladium are used as an oxidization catalyst. Cerium, iron, manganese and nickel are also used, though each has its own limitations. Nickel is not legal for use in the European Union (due to nickel hydrate formation). While copper can be used, its use is illegal in North America due to the formation of dioxin.

I'm no chemist but I believe all of the elements listed are metal sans silicon. I do understand that a chemical reaction takes place due to these various metals reacting with spent exhaust gases to reduce hydrocarbons etc. Yet they are all metals.

[CRXperiment]

Originally Posted by turtlecrxsi

I'm no chemist but I believe all of the elements listed are metal sans silicon. I do understand that a chemical reaction takes place due to these various metals reacting with spent exhaust gases to reduce hydrocarbons etc. Yet they are all metals.

Well generally all those transition metals you talked about are recycled and regenerated throughout their reductions and oxidations. This is why a cat should generally last the life of the car, unless loaded with tons of unburned fuel for long periods of time.