I changed my exhaust system to a 3" stright through to the muffler and nothing else.there was a hose conected to my cat. converter that went back to my motor ,does that hose have to be closed off or left open.......if some could reply and help it would be appreciated.

thks Frank

 

Is that where it goes? I recently took out my midpipe to replace with the cat and saw that hose but had no Idea where it was supposed to go. It was plugged up from the last owner so I just left it plugged. I thought perhaps it went to the pre-cat and thats why I had no idea where to put it.

 

It goes from the air-pump. It pumps air into your cat to get it hotter to burn more emmisions.

 

All it does is pump fresh air into your cat, when i added my midpipe i just plugged it up...

 

its one of the mystery hoses from the intake box right?

 

It goes from the airpump to the main cat. I recommend hooking it properly, or else your cat will likely lead a short life.

 

ah, perhaps I was confused because I have no airpump. Oops...

 

can the hose be plugged if you still have the air-pump?

 

just take out the air pump, as far as I know you dont need it if you are running no cat, saves weight too.