Something broke off under my 84 z28.. its a pipe that runs along next to the exhaust system maybe like a 1inch diameter pipe..its probably 3-4 feet long.it isnt held by brackets but instead by wires wraped around the exhaust pipe to the muffler...im not sure what it is..my car starts up fine and turns of fine also...my gauges seem fine...no smoke is coming out of it or liquids although it did leak 4 drops, but thats about it...


here some pictures...its night right now...and it was from my phone...

 

does it go into the cat?

there should be no pipes along your exhaust other than a POSSIBLE AIR system tube that runs into the cat converter. even then it should only run to the cat converter

 

Looks like the air tube to me. Start the car at idle, and see if you can feel air puffing out of the tube.

You could probably fix it with some of that high-temp metal exhaust tape from autozone or wherever.

 

Thats definetly the A.I.R. tube. I've owned my '84Z for 16 years and can't tell you how many times I've had to replace it. It attaches to the catalytic converter, then runs up to a check valve on the passenger side exhuast manifold. If someone else hasn't lost it, there should be a clip to attatch it at the back of the pass. side head. Its supposed to help releave the stress off the check valve. The place where it broke on the cat. is the weak point. Every one of these that I replaced rotted through in front of the cat's. out pipe. The biggest pain about doing this replacement is that it is almost IMPOSSIBLE to change it without putting the car Way-Way up in the air.Muffler repair tape won't last. It gets enough pressure to just blow right through it. Sometimes you get lucky and can just cut off the rotten part, bend some of the slack out of the length and reattach it. I tried going to the hardware store and buying some plumbing pipe one time but the galvanizing reaction rotted through faster than I expected. The best thing I came up with so far has been to go to the junk yard and get a tube off one there. Then I went to the muffler shop and they welded a couple of inches of the tubes together for me. Save the rest of the scrap tube though, you'll need it again in about a year.

 

If you haven't solved your problem by now, like everyone has said, that's the AIR tube to your cat.

There's usually enough movement of the tube to allow you to cutoff the damaged part and still get it to line-up and connect to the cat. So if you can get the two ends close enough, then you can connect them with a compression fitting from the hardware store. You'll find them with the natural gas line parts.

Otherwise, muffler shops have air tube repair kits for about $40. Naturally, some shops want to do the repair themselves rather than sell you the kit, but most would sell you the kit so you could do it yourself.

Running broken probably won't affect your engine's ability to perform. But be sure to repair it before your next smog test, or you'll fail.

 

IDK about you guys having the air tube rot off, but I think mine is stainles. Its kinda shiny, and doesent have a speck of rust on it. They y-pipe itself is a different story, it has some pretty bad surface rust.

 

You're right. It should be stainless. Mine is, too. When I replaced my cat, I had to cut the tube with a tube cutter.

Looking closely as his, I don't think it's the tube that rotted. It looks like it's been patched/repaired in the past with a rubber hose, and that's what has rotted. Maybe the tube got damaged in the past and needed repairing. But probably the car got a new cat sometime in the past, and the tube was cut and patched.

So a proper repair kit is probably all he needs.

 

I no longer have an AIR tube. My cat isn't even made for an AIR tube connection, yet I pass emissions testing with flying colors, on my 165,000 un-rebuilt 350!

It helps that the cat is only 2 years old.

Put a new cat on, toss the tube (just leave the manifold/header pieces in place) and you should be good.

 

My air tube to the cat has a little mini clamp on it, and it's slip fit. So if I ever take my cat out, i *should* be able to loosen the clamp, and un-slip the air tube on the y-pipe from the air tube on the cat.

 

Yes, mine is stainless also.The key word though is steel. A derivative of Iron. It rusts,rotts,cracks,pitts,and genarally fails, given time and natures elements.
The connection at the cat. is in an extreme enviroment. The tube gets crushed by a clamp, usually onto an inferior type of metal, the out pipe from the cat., which is rarely made of the same grade of stainless. Then there's the fact that the place that will begin to fail first is right at the tip of the out pipe, probably helped along by vibration. The extreme swings in tempurature from ambient to exhuast tempered. The outside gets blasted by all the sand,pebbles, and general debris left on the roadway as you drive down the road. Here on the third coast you then have to factor in the humidity, its usually very humid most of the year, that's why my car expells as much as a full cup of water from the exhuast every time it starts up cold.The fact that the tube is very thin gauge to begin with, doesn't leave you with much protection, before it sucummbs to the elements.
I call it rott.
I agree that the picture looks as though the tube was repaired in the past with some kind of rubber sleeve. That's probably why it was hanging from the car, instead of making a bad exhuast leak sound first, before it was discovered.

 

Yea my car just had that problem so right now its a minor deal to me. I got to shave off some rust on my wheel wells. Any tips on how to do it

 

Does anyone have an idea of where to get an entire one? My car is missing it completely. The check valve is still there, and the pipe on the cat but nothing in between. Will a length of rubber hose work? Even temporarily just to pass the visual emissions checks? I only need it on there to get the car inspected once, then I can have it exempted from future emissions inspections. TIA.

 

Try looking in a junkyard these things are everywhere.They should be cheap as well.