I've long removed any and all emissions ftom my car but would possibly like to put a high flow cat back on. I would like to know if I can just put one back on without the air pump and pipe that brought air into the cat?

 

Yes

 

yeah but why? You are better off adding a magna flow or borla xr-1 oval in the center than a cat.

 

You can put the cat back on, however without the air pump, you will loose about half the effectiveness.

3 stage Monolithic cats need the air to complete the scavaging process.

 

What would adding another muffler instead of a converter do?

 

People think it will net them more HP...

of course it doesn't