Haha yes! stumbled across this tonight, basically it hasn't always been like this, there was a stud there.

Whilst I was scouring for leaks, I thought the mani looked a bit for away from the block.. so I decided to tighten up that nut. The stud just snapped straight off. I think it had been fucked about with by the previous and they just bodged it back in or something.

Anyway, it's not actually blowing. Which is confusing me as to whether this would actually be the cause of the bad emissions?

I think I may have posted this is another thread here.. but I basically think that if there is air getting into the manifold, it will go past the lambda sensor which will sense the extra oxygen, and will think engine is running lean.
So will get ECU to inject more fuel, which doesn't get burned..

So the extra fuel doesn't get fully burned and comes out as CO
And the air that got in obviously isn't burned either, and comes out the back and is picked up by gas analyser and it fails on lambda aswell. Just like a normal exhaust system blow.

What you reckon?