Old thread, but I got to searching about foam insulation around knock sensors. My '13 has a foam insulation under the lower intake that pretty much fills the whole knock sensor valley and the pics I'd seen of Z28th1s's manifold swap...didn't have anything there. You could see his knock sensor valley in the pic. MAYBE it's there for simply cancelling out some engine noise but maybe it also has a dual role of isolating the knock sensors better to detect knock?? Just putting that out there. I've seen on other platform forums that a few people were saying this. I don't know if it's correct or not but it seems it might isolate ambient noise to an extent so the knock sensors could detect the knock frequencies transmitted through the block better. Sound like a possibility?
Anyone else have the foam under their lower intake? I might need to start a new thread.
I have the foam 'insulator'... I was told by a Ford Tech at my local dealership that it was placed there to limit noise from the injectors.