For a while now I've had a rattling cat on the passenger side. I suspected there wasn't much left of either cat and now that the misfire and everything else engine related seemed to be sorted I had a new set of cats fitted today, so now have a full stainless exhaust (as I had a stainless cat back install last year when the back boxes started to give up). However it has now highlighted the rattle/tick noise that has been there for a while, but now that everything else is quieter, it's more obvious. I also blamed some of the noise on the rattling cats.
The exhaust shop also mentioned it today, as he said he couldn't hear anything from above/with the bonnet shut, but whilst he was underneath it was pretty noisy at idle. He said he's never really heard a noise quite like it before though and certainly can't point to what it could be.
He's right, it's difficult to hear in an open space with the bonnet shut, unless you bend down. It can be heard from either the drivers or passenger side if you get down low, but a bit more pronounced on the passenger side.
It's there at idle and can be heard at low speeds under acceleration if the passenger window is fully open. If the drivers window is open and passenger shut though, it's almost impossible to hear, which makes me think it's coming from the passenger side somewhere. With the bonnet open and head in the engine bay, it can be heard, but no way near as much as if you get your head down behind the front passenger wheel.
I'm convinced it's become louder than it was a couple of weeks ago, as it's hard to ignore now.
I've tried to capture it on video - this is with the camera held behind the passenger front wheel, reaching inwards. It's the slightly higher ticking/rattling noise that can be heard over the deeper exhaust noise. It is there from cold and will still be there after the engine is fully warmed up. It's also there in park and neutral too.
Any ideas where I should start to investigate?