Hey guys I was just looking at my engine bay while waiting for my heads to come back from the shop and I was looking at a metal pipe that connected to the stock exhaust manifolds. The pipe went under the engine block and comes out and connects to the other exhaust manifold. What was that used for?

My guess is its from the egr setup. Correct me if I'm Wrong

 

most likely it is the egr/a.i.r. injection system

 

That was exactly what I thought

 

took my air pump off and pluged all them lines and holes including the exhaust manifolds/headers, pcm didnt notice a thing on my 93 z.. no emmision testing here.