It is very hard to diagnose a problem that without actually being there to see the whole equation. I have installed many many plates and can tell you that the plate does not by itself increase boost pressure. The plate install might.
About the detonation problem, what might be happening is you have a weak injector and without the power plate the air flow going to that cylinder is also low and matches the injector output. After the plate install, the cylinders are all receiving equal amounts of air making the cylinder with the weak injector lean.
Hope this helps.

About the detonation problem, what might be happening is you have a weak injector and without the power plate the air flow going to that cylinder is also low and matches the injector output. After the plate install, the cylinders are all receiving equal amounts of air making the cylinder with the weak injector lean.
Hope this helps.