PID issues

I have upgraded my HICTOP 3DP08 to dual nozzle and am having issues with PID values.

Because my original firmware did not account for a second nozzle I had to start from scratch in Arduino.

With my initial configuration.h my bed was heating so slow that it timed out and my new nozzles were heating way too fast and overshooting causing MAXTEMP errors.

I managed to autotune my bed successfully but my new nozzles were so wild I could not get autotune to work without hitting MAXTEMP.

I changed PID_MAX in configuration.h from 255 to 125 and it fixed my nozzle problem but, surprise, my bed won't heat at all now.

Which variable, P, I or D, should I tinker with to resolve this problem?

Thanks in advance.

Just a thought... I'm using the PID for my heads but bang bang for my bed. Fried my first RAMP with PID on bed. I had no fan and it destroyed the MOSFET. I haven't tried it since, and honestly, see no need for it. Bang bang seems to work quickly and accurately for me.