**1984 Pontiac Fiero SE 2m4** I've been rebuilding this Fiero and I have decided to replace the exhaust manifold, i ordered a new one and im a bit confused. the small little pipe that comes off the back of the exhaust manifold (circled in picture of manifold on table) I have learned (correct me if I am wrong) is called the heat exchange pipe?? I took a look at my current one in the engine and it is a lot larger and is currently connected up into the air filter cleaner housing. However, I have seen other engines with a heat pipe that connects into that spot on the filter housing and then goes down into the exhaust below. So im trying to figure out: A. what is the little pipe hanging out of the exhaust manifold B. Does it need to connect into anything? C. and if it does NOT connect into anything then where does the outlet on the filter housing where it is currently connected into, supposed to connect to?

Sorry if its a bit confusing, this is my first project car and I'm learning as I'm going so not quite sure what everything is called yet. Thank you for any help! its much appreciated!

[This message has been edited by FranklinTurl (edited 10-15-2021).]

Looks like that replaces the stock one that went down below. The one I saw from below simply had a metal shield around the exhaust pipe then a flexible hose up to the filter canister. I always heard it called a heat riser. It lets the warm air off the exhaust rise up and enter the filter canister through a thermac valve in the filter canister. Its purpose is to provide warm air to the throttle body to prevent icing, until the engine warms up.

As mentioned above, you attach the pipe from the air filter housing to that pipe on the manifold. It should fit fine.