Originally Posted by CmptrNerd
Wait that thing about the metal EGR hose. Wont there be a hole in the exhaust manifold? And whats it for anyway?
For the hose/hole, you either cap it or put a block-off plate in -easily made or can be bought from www.Intense-racing.com
EGR -Exhaust Gas Regulator
It sucks unburnt gas from the exhaust back into the intake, thus improving MPG'* ever so slightly (maybe up to 1 MPG less), and at the same time helps to prevent burnt valves. The 1991-1992 L27 did not have the EGR system as they passed emissions with flying colors without it, but they had a few problems with burnt valves, so they re-applied it in 1993.
Most people do this as a means of gaining 2-3 HP, while others do it to prevent the upper intake failure. I personally have yet to do it myself, but I will do it no doubt over the next month or so.