The Monty's are notorious for cracked manifolds, specifically the driver side. My buddy just replaced the one on his 2001 and they are not cheap...like 200+ a piece. I however didnt wanna shell out that much for mine so I went down to the local AirGas store and bought me some Nickel welding rod and welded it up. Mine was cracked just about all the way around and was messing with my O2 sensors and sending a check engine light. All total...was 10$ and about an hour and half of my time to remove and re-install it. Was easy as pie and tons cheaper.

If you cant get Mitsu dealer to replace it under warranty, (which you still should persue) I would just do like I did. <img src="/forums/images/graemlins/kewl.gif" alt="" /> <img src="/forums/images/graemlins/kewl.gif" alt="" /> <img src="/forums/images/graemlins/smile.gif" alt="" />