Glad this car went to someone that is going to do road course work. I'm sure John made it significantly more capable than it was under me when I basically made it a dyno queen.
If you ever have any questions about the engine build (i'm assuming John gave you everything anyway so probably not)...
I was and have been using Pennzoil Plat. Euro 5w-30 or 0w-40. Whatever I found. Car burns zero oil at 3.5k oil changes.
I think the most logical explanation is the rings basically re-carboned themselves and brought the compression back up in all the cyls because when they were decarbonized...
Check the ground wire (little tiny black wire) on the coil harness.
Also inspect your High pressure fuel sensor (left side of the fuel rail). @Maisonvi got the same code from smashing his sensor w/ his JMF manifold.
Meh a stock diameter sized intake will do basically nothing on a non-tuned...
This will depend if he has his Knock sensor set at the most sensitive load settings.
Personally it sounds like its some noise in the motor. I'd mask it in those RPM's (make the knock sensor less sensitive) and continue tuning if it were me. I know Sari (Ge3kSpeed) had the same issue on his...