So I had one of those track days yesterday when the car just had gremlins in it.
On an out lap I heard my induction noise suddenly change to a very metallic, raspy sound. You could hear the turbocharger working very clearly and it sounded initially like a bearing had failed. I foolishly ran around for a few laps because the car was still running completely fine.
After I pulled into the pits I popped the bonnet, I thought it was an intake problem but it turned out the top O2 sensor had blown clean out of my DP and was hanging around by the wiring. In this pic you can see the hole where the bung should be and the sensor itself is a bit blurry hanging to the lower left of the hole.
The result of this kinda turned my DP into a screamer pipe - hence the added noise. But this also vented exhaust gases straight into my engine bay and all over the back of my intercooler:
That's one sooty intercooler.
It also partially melted my intercooler shroud, and some other plastic parts around the site of the problem are slightly melted as well. Some of the foil heat shielding is also slightly damaged but it looks like mostly did its part in mitigating any damage.
I took the car to Tunehouse who are patching things back up but they have also told me that not only was the O2 sensor thread stripped and ill need a new one, but the DP also has a crack in it. Exactly where and how bad I do not know, we will sort all of that out next week. I have a CP-e dump pipe FYI.