Pre-ignition, detonation at wot in 3rd & 4th gear

[LJ851]

WOT switch is a possibility. If the switch doesn't close, you are running with the higher advance numbers of the part throttle map. You might blast through that area fast enough in the lower gears to not really notice it.

[Hoffbrohaus]

what engine mods and specs etc if applicable?

M20B25 sorry I always forget about the 4cyl brethren
M20 MAF, Big bore throttle body, 19# injectors, custom chip for 19#ers and 91 octane.
Not sure if it matters, but catless supersprint exhaust.
Also forgot to add to the list of recent fixes a valve lash adjustment and new fuel filter.

[digger]

what engine mods and specs etc if applicable?

[Hoffbrohaus]

I'm hearing detonation around 4.5k-5k rpm at full throttle only in 3rd and 4th gear (maybe 5th too but don't want to go to jail). 1st & 2nd are fine all the way to redline.

I have done the following while chasing this...
New FPR
New o rings on injectors and cleaned. (19#ers btw)
New plugs, new wires, new coil
Checked cap & rotor looked good (no carbon anywhere and tips were fine)
Installed wideband o2 and afr gauge, afr looks good - 14 and gets richer at higher rpms 12 or high 11s when the Pre-ignition occurs.

What do you guys think?

I'm also having a long crank issue but not sure if it's related. Fuel pressure checks out fine just not holding when pump is off.