[Saudade]

You need to be a bit more descriptive. Is it a regular click or somewhat random? Does it change with RPMs? Does it continue after you shut down the engine, while it's still hot? Without the stethoscope, you should be able to narrow the location to a general spot (like driver/pass side, front or back).

It ran fine until you discovered it has an exhaust leak? How did your discovery make it run badly?