So a couple of months ago I had some hooker long tube headers without air/egr put on my 93 z28. Basically I've had the hoses uncapped assuming all they would do is blow air into the exhaust manifolds. I was looking at an air and egr diagram and it looks like the piping goes into the intake manifold. So I was wondering if it was vital to cap the hose's, or if my original assumption was correct.

 

Be a little more descriptive as to what you have uncapped and such.

 

From what I can tell, the hoses that are uncapped are the ones that originally went in the stock exhaust manifolds.

 

On the AIR pump side, it's just going to blow air out when the pump is on. If you just unplug the electrical connector to the pump and leave a good fuse and relay in place, the pump will be disabled and you won't get a check engine light. You could also delete the pump and it's pipes.

What about the EGR? What's done at the back of the intake manifold? If the EGR valve is sitting there with no vacuum source connected to it, it will act as a block off (as long as the valve does not leak when closed). Or you can remove the valve and put a block off plate on it. Normally people also block off the exhaust inlet to the manifold, too (though it just serves to cover the hole).

 

Thanks for explaining that. I didn't realize that the EGR valve would close if nothing was connected to it, and was worried that I might have vacuum issues.