Ok I have a redtop sr20det that has a bad exhaust leak. It sounds like it is coming from the no. 3 or 4 cylinder area. I took the manifold off from the block and the gasket looks ok and I couldn't see anything wrong with the manifold it self. I'm pretty sure that it is pre-turbo, the turbo isn't spooling up like it is supposed to but it does go from vacuum to a couple of pounds of boost. Does anyone have any idea of where to look next?