Smog pump/HVAC/Exhaust/ and Vacuum problem

[86GmLsCoupe]

I was in the process of prepping my Grand Marquis for when i fix the a/c later this week. I removed and unsiezed my non-functioning smog pump (cat air-tubes are capped), and reinstalled the pump (I want to keep the pump for the pulley). I removed the metal air tubes that go down to the cats. Another metal tube from behind the engine that connects (by rubber T) to the the air tubes cracked. All i know is that the tube goes behind the engine but i can't figure out what it is and what it's for. I capped it because it seemed to be releasing exhaust into the engine bay. All the other tubing for the smog pump was removed and the two vacuum lines that go to it (colors Pink, and Black) were capped off. My questions are:
1. What is that metal tube that goes behind the engine?
2. Can I leave it capped?
3. Is it alright to just cap off the black and pink vacuum lines that go to the smog pump?
Unfortunately i don't have a book for my car and my EVTM hasn't been any help and I'm completely lost.
Thanks

1986 Grand Marquis LS Coupe [/url] http://photos.yahoo.com/leo76830

[Grand Marquis GT]

That line is for air injection. In order to block it off, you can remove it, it bolts onto the back of the heads, cut the tube off, and bolt the little end plates back on, but backwards.

This will free up that exhaust leak.

Ive done it to a few panthers already!!

[86GmLsCoupe]

I just wanted to make sure that this was the air injection tube (behind the trans dipstick).

http://pg.photos.yahoo.com/ph/leo76830/detail?.dir=/28f8&.dnm=25ec.jpg&.src=ph

I used this temporarily to cap it off until i can do what you were saying.

http://pg.photos.yahoo.com/ph/leo76830/detail?.dir=/28f8&.dnm=3e1a.jpg&.src=ph

Thanks Again

[Grand Marquis GT]

That will work for a very short time, thats hot exhaust gas!!


And yes, thats the line I speak of....