PS1 emulation problem with certain cheats

[kh2k4]

Has anybody found certain codes have no effect with PEC and Dr.Hell's CEP and Action Replay GPU Wrapper as well as cheat engine for instance the following doesn't update fast enough and constantly flickers on/off in CEP, has no effect in PEC and with cheat engine it only stays on when you click the cheat engine tab when swapping between the emulator and cheat engine, what's the problem can't these programs tell the emulator to update fast enough with certain codes? because I tested the code with action replay v4.2 through the emulator and it stays on constantly as normal.

Gran Turismo - PAL
Look Behind
300BC061 00??

00 - Always Off
01 - Always On