'91 300CE M104 - exhaust leak at pipe to manifold

[rgnprof]

I don't know if this is causing some of my driveability problems, etc, but I have a rich-running '91 300CE with a very noticeable exhaust leak where the rear exhaust pipe connects to the rear exhaust manifold. Rev the motor and you can see black smoke blowing out the joint...

Is there a gasket here or not? I don't see one on the online manual...so if there's no gasket can I just tighten it up - or is there some other reason for the leak?

Thanks,

Ryan

[i6h000]

No gasket, metal to metal fit. Make sure the flange holding the pipe to the manifold is straight (bolts tightened evenly).