Originally Posted by F1TwoThousand

So went to take a look at the cylinder head. Even though the S2K doesnt have an egr there are benefits to plugging these Secondary air injectors shown. There are 4 total seondary air ports 1 on each exhaust side of each cylinder. Plugging these up will keep the ports from filling up with hot exhaust gas(especially if boosted). Also keeping these ports filled with hot gas heats up the aluminum cylinder head. So basically plugging these 4 ports is a simple mod that will keep some heat soak away from the cylinder head and enable the cutting off of the egr looking thing on the intake manifold which in turn frees up space to work on behind the engine by the firewall.