I replaced k03 with k03s on a M3.8.3 system, before I was having a perfectly smooth boost control with zero oversohot and oscillations, now I get slight overshoot (~0.2bar) and oscillations about +-0.1bar (at 1bar) at around 2Hz. The k03s feels like it has a faster onset of boost, so does it need PID tuning? Also, the exhaust housing on the k03s is slightly cracked (hairline cracks), but it does 1bar at 2krpm so not much leaks, could this be the problem? I also tried altering the actuator preload, I tried 2 and 5 turns from zero position with little effect.
What are the relevant maps in m3.8.3?
Edit: I think I may be on to something... I found KFLDP (proportional gain) and KFLDI (integrating gain), but KFLDD does not exist.

Edit2: Further investigation returned that there are probably two maps for the D gain - DLDRN.0 (D-component) and ZDLDRN.0 (time constant for D-component), not sure why two maps..
Thanks