i have a 1984 camaro z28 with the 5.0 HO and i was just wondering what the metal pipe that runs from somewhere in the engine and plugs in to the cat does. also what would happen if it was blocked or mashed flat.

 

That's your A.I.R. pump tube. It'll only effect emissions.

My cat is gone, my smog pump doesn't even have a pulley on it, but my cat is only a year old. My emissions results a few months ago, were practically nothing, due to the new cat.

 

So if you was to remove your cat do you just let the tube sit there or do you have to plug it?

 

The previous owner swapped the cats. I've never even looked under the car, to see what he did with the tube.

I would just secure it up, or remove it. Not positive, but capping it off, might be a bad thing to do. If your pump is hitting a wall, where would the air it is pumping, go to? There might be a built-in bypass valve.