Is the MAP sensor on the GEN V a 2 bar sensor?
What size pulley is on your GEN V?
You're using a GEN V with a L67 tune? You say you can hear the valves pinging.
Sounds like detonation due to:
A LA Bill - Vacuum leak or bad/wrong sensor - lean condition
MAF tuning is way off. Was the L67 tune previously modified?
You're using 33# injectors?
KR mostly causes the engine to lose power, not hesitation, unless engine is detonating.
Ideally, the PCM should be optimized for your particular setup.
Knock sensor DTC's = P0325 through P0334
