ok i have a couple questions. what size is stock exhaust piping, and for aftermarket exhaust should i get 2.25 or 2.5??
Not sure of the O.E. sizing for the ecotec years. But to answer the last part, IF you want to stay N/A then def stick with the 2.25 and if your planning on forced induction then get you some 2.5 at the least.