1999 Toyota RAV4 took a big hit to the exhaust system (near the rear) yesterday on a logging road. Afterward, there was increased engine noise: I concluded immediately this was an exhaust leak induced by the impact. There is a tennis ball sized dent where the impact occurred, near the rear of the vehicle, but there is no leak there.
The added noise is coming from around front of the car. I felt around and found smoke puffing out at the joint between the exhaust manifold and the downpipe. I replaced the gasket in this joint and the puffing went away: the joint is now airtight. However, the noise only intensified.
It is difficult to identify the source of the noise. I don't feel any other puffing. I felt around the manifold gasket too, and all along the front exhaust system. The noise intensifies when the engine ramps up.
Any suggestion for an investigation or approach to repair would be appreciated!