I know mufflers are directional, but does anybody know if cats are as well? I don't think that they are but I wanted some confirmation. & I am not talking about the arrow they put on it so you can properly line it up with flanges, pipe size etc. I am looking for a rational explanation.

 

I have a Catco high flow cat and it has a big arrow on the heat shield that says flow in it. So mine is. I cant say for all cats though. I would guess that if it is not marked then it is not directional.

 

Cats are multi-directional if you put tape on their feet (sticky side on the feet, smooth side down). Just Kidding. All cats are flow directional, indicated by either an arrow or by design of the flanges so they can only be installed one way.

 

so what happens if you install in the opposite direction. looking at the design it appears to be the same either way. This was a generic cat with no flanges. On the initial install the welder screwed up the flanges and it had keaked all along, now that it has had the other flange put on we had to flip it around because the toyota flanges are flow specific (one male on female). What would be the concequense of this?

 

Some cats are bi-directional. Magnaflow is bi-directional, thunderbolt is bi-directional. Eastern is directional. Catco is directional.

I'm not sure what will happen to install a cat the wrong direction. My guess would be lack of flow and possibly clogging.

 

some cats can go etheir way but if it is a dirctional one you will know it will plug super fast

 

how and how fast?

 

You will know if your cat gets clogged. Your trcuk will most likely start sputtering pretty bad. How fast? I can't answer that question.