Hi guys, I found this small metal pipe, about 1/4" ID, broken and lying in the engine bay. It seems to go down to the exhaust, next to the O2 sensor, but I don't have the chance to go check under the car now. Can someone explain me what it does? The broken part had a cap on it, so it wasn't connected to anything. Any idea?

 

It is a factory CO test pipe. Mine fell of too. I think you can cap it off with a lug nut or weld the hole.

It’s #24 in the diagram

 

Cap was originally 035.133.335.B per Technical bulletin Book C, Group 2, Number 8605, 19 Sep 1986. Appears superseded to 034.133.335.D.

 

Funny, I never noticed that tube sticking up on my car, so I went to look. Mine's broken off in exactly the same place. Now looking for something to cap it off properly.

 

What's funny too is that I never noticed an exhaust leak, and I guess that open tube should be enough to notice. Maybe my car is overall so loud that I couldn't hear....