There's a hose that's supposed to be open (going to nothing),and that could be it. Looks like somehow it got pinched shut over time.

 

It could be the the vapor canister hose as described in this thread starting around post7.....

http://www.impalassforum.com/vBulletin/showthread.php?t=345905&highlight=Evap+hose

The cars I've seen have it in the fender well area. Some have described this also being in the battery compartment area. Maybe yours was crimped or sandwiched between the inner fender and battery tray somehow? If you trace the hose back and it goes to the charcoal canister then you found the right hose.

The diagram in the link shows how these hoses are all connected. Good idea to replace them if they are original.....beware - they will be a sooty mess.

 

Where is this supposed to go?
It's coming off a tee between the battery and the headlight.

Semi-permeable fuel hose for the EVAP canister vapor evacuation. It degrades into black dust w time. There's been enough time. Replace it w/ like hose. If there are leaks or degradation of the hose, vacuum related issues arise and the EVAP canister purge solenoid can become clogged w/ the hose dust.

 

canister vent hose is what that is. I replaced all my fuel tank venting hoses behind the bumper last year. make sure you use gloves because that rubber is like black glue very hard to get off your skin...the hoses get so soft they get pinched and block flow of tank venting thru canister.

being hidden you don't see it all.. problem I had was too much fuel tank pressure.... after hose replacing ALL at the canister no more high pressure with fuel tank cap removal.

with the hoses breaking down sure can block the purge valve..so replace that hose also..

 

Went out and had another look.
It seems the other part of the t is not connected either.
So these just vent to atmosphere I guess?
Here is the pic from the other thread.
These would correspond to part 5 and 6.

 

That is correct, if you look at the picture of mine in the other thread, you will see the tee with 2 sections of hose that go to atmosphere. Part number 5 is just showing the hose(s) that are used. While part number 6 is the plastic tee that connects them.

I think laying in the fender is best for this hose as its away from things and can't possibly be damaged like how yours was. You can see how that is from the pics I posted. Don't have any info or pics of how exactly it lays in the battery area/behind the headlight.

If you decide to do anything with the charcoal canister, it is behind the right front bumper and mounted to the side of the frame. You just need to remove the plastic fender extension (right air dam corner mounts to this) to get full access to it and the hoses. Iirc - there are just 1 or 2 10mm bolts that mount the canister bracket to the frame.

 

Yah I figure if I fix it I should get 10 more horsepower, shave some tenths of at the track, and get 5 more mpg...

 

Absolutely, and if your car is Black, then you have the Faster Color too.

Don't be confused with the number of hoses on the "T". As there would be with any "T", there are actually 3 Hoses attached, not 2. Not sure I saw all of the hose(s) in your Picture at the beginning of this thread. As pictured below with the original hoses before I replaced them...1 hose comes off the Canister to the Tee and then the other 2 ports of the "T" has a Short Length of hose on the middle port and another hose that is a little longer on the 3rd port. Do you really need both hoses? Probably not since they both just vent to the atmospere but this is how I found them. If you look closely at the pic you will see they are the GM Hoses.

The other picture in the attached link is with the new hoses attached and tucked back in the Fender area how I had originally found them.

Well further to the mystery, when I replaced the fuel pump on this car I found that the tank vent was not connected either, like the line had been cut a couple inches up from the tank. This I fixed.

hmm I'm thinking that perhaps a previous owner had some drive-ability issues and was running rich and smelled like gas.
And perhaps made some modifications to hide the issue.

Its anone's guess what was done to the car over the years and by previous owners. Some of the stuff I've seen "rigged" by previous owners just makes you shake your head in disbelief. The hose you mention I assume is back by the Trunk near where it attaches to the Sending unit or in that general area? It's pretty common for that hose to be off, whether removed and forgotten or just cut somehow, we've seen that issue before described by other members.

I've noticed some excessive pressure issues lately with my tank and suspect that the Charcoal Canister may be clogged or something. The purge solenoid can also become gummed up with particles/charcoal from the canister. I need to take a closer look at the canister since it is original.

I've seen threads on other Forums where they have rebuilt the Charcoal canister using pellets you can get from a Fish Supply Store. I have a spare canister I can swap on the car for now and may take a closer look at rebuilding one to see how it goes. I believe you can still buy these new but I'm a cheap SOB and will try to rebuild mine first. If I do, I will post up a thread on whats needed and how to do it.

Edit - This thread has info on the hose you may be asking about. also a link in there to rebuild the canister. :>)

http://www.impalassforum.com/vBulletin/showthread.php?t=335513&highlight=evap+canister

 

that T only has 2 hoses so what you got is how it was built.

fixing this will not give you more HP or MPG. it will help on idle smoothness and insure the fuel tank vents properly..

if you race with this car remove the ac and all the other parts . this will improve race times.

make the car lighter ..

 

.. if you race with this car remove the ac and all the other parts . this will improve race times. make the car lighter ..

If you race this car, remove the serpentine belt. It saves the HP that it takes to run the alternator, etc. and you don't need power steering to run in a straight line (other than the turn at the end).
Run it on the battery, then put the belt back on.

Yes your WP will still work, it's driven off the cam, not the belt.

$0.02

 

Well further to the mystery, when I replaced the fuel pump on this car I found that the tank vent was not connected either, like the line had been cut a couple inches up from the tank. This I fixed.

hmm I'm thinking that perhaps a previous owner had some drive-ability issues and was running rich and smelled like gas.
And perhaps made some modifications to hide the issue.

 

that tank venting line at the rear of the vehicle transfers from a 3/8 inch rubber hose to a smaller plastic tube hose about 1/4 inch. what you will see going to the front of vehicle is a 3/8 rubber hose but inside of this is the smaller hose that must connect to the larger rubber hose venting from the tank. the reason the smaller plastic tubing is with this rubber hose over it is to protect it as it travels forward toward the canister. around the right rear wheel frame area...

these fall off very common problem at this age ... happened to me last year. it just fell off . I had to cut some of the rubber hose off that protects the smaller plastic tubing to get my hands on it and make the connection.

 

Yah, no racing in this car's future.
I'm just getting it ready for licencing.

I think that since these hoses have an "exhaust" type of function that the line off the "t" is in fact a drain.
So that when water accidentally gets in the open end of the straight thu pipe it has a place to go other than down into the evap can.