yep, the rear lower exhaust stud on the exhaust manifold is gone. Been hearing a loud exhaust leak for the last 3 days, couldn't locate it exactly until I took some action today.
I knew it was either where the exhaust header mated up with the exhaust pipe or somewhere on the manifold.
Took off the air cleaner and air intake, removed the heat sheild, whipped out a 14mm socket and proceded to tighten if possible all the exhaust manifold nuts and the header nuts, nothing budged. Hmmmm...
Put everything together except for the heat shield and fired it up. Sure enough the exhaust leak was louder and I could feel exhaust being expelled by a hole that looked like it needed a stud in there.
I'll get a new stud come Tuesday when the local Toyo dealer is open again and hope that fixes it and no damage to the exhaust manifold gasket occurred, otherwise I'll be replacing that gasket too.