perna,

Try Axle's tip before you take an impact wrench to the exhaust and manifold bolts. A good soaking with a penetrant does wonders. There is nothing worse than snapping off a fastener; especially a stud. As a last resort I've used a small propane torch (AKA "Heat Wrench") to free really bad fastners on the suspension, frame and exhaust. Use extreme caution and common sense when applying this technique!!!!!!!!!! Darwin is always watching!! I only do this outside with fire extingishers close-by and after checking the area in relation to any systems and their corresponding lines;ie: fuel, electrical, etc...