Diagnosing source of exhaust leak in engine bay...

[Aubec]

Hi guys,

I\'ve got an exhaust leak somewhere in the engine bay at the moment. I\'m pretty sure its not at the downpipe, as I had the leak before I swapped out my standard Pre-cat for a HKS downpipe - the gasket looked fine, the DP flange seemed smooth enough and I\'m reasonably happy that I tightened the nuts down properly. Realistically this implies a cracked or loose manifold or turbo hotside doesn\'t it?

I need to get to the bottom of this, but unsure of whether its feasible to find the source of the leak without dismantling and inspecting the turbo pack and manifold. At the moment the car drives and boosts fine, but I know if I start dismantling it\'ll be off the road for weeks - I\'d rather carry on driving for the time being while I figure out the problem, buy whatever new parts are needed and then dismantle/reinstall over a long weekend when I\'ve got all the new parts I\'ll need to hand.

So... advice please - how to figure out the location of the leak?

Oh, and is an exhaust leak in the bay grounds to fail an MOT?