Certainly looks lean.

Have been in the car though (that night in fact!) and it certainly wasnt lean on the wideband monitor he has installed cause i was specifically checking when he took me out in it cause i find such things interesting due to being a techy nerd, lol!

blocked injector maybe?

rings on that cylinder not sealing (poss due to bore wash) allowing oil in which lowers the octane rating and encourages DET



At a bit of a loss to be perfectly honest Si!