If the Cat is designed to burn excess exhaust gases causing the heat, how is making the engine richer going to reduce the heat. I would think the more excess fuel the hotter the Cat. Confused

 

Richening the fuel reduces motor head temps, the exhaust is still very hot. The cat gets hot because of the hot exhaust. It retains the heat to do it's emission magic. You have to remove or shield the cat to lessen exhaust pipe heat.

 

So are we saying that in order to reduce the heat we have to remove the Cat? Richening the fuel mixture will only have the engine run cooler but you will still have the heat from the Cat.

 

what application?

 

Yes, the cat will get very hot regardless. They are supposed to.

 

Right. The metals in the cat don't "activate" for lack of a better word until a certain temp, and it's hot.

 

Here's the only cat I have now. Anybody want to buy a stock header? You can drill out the cat.