Accelerating from a standing stop I get a sound like an exhaust leak. I changed the header pipe gasket 1st, no change. Cant see any cracks in the exhaust manifold and nothing loose down the exhaust system. I cant see inside the muffler but its quiet in the back? Any ideas where else to look of how to do a "shade tree" test? BTW the fuel pump is very noisy tap, tap, tap.