VT 5.7L Oxy Sensors

[ROBBO_308]

Hi everyone was wondering if anyone could help me.
I've got a vt ss 5.7L and the engine light come on so we put the scan tool on it and it come up with p0133 Left oxygen sensor slow response and p0153 Right oxygen sensor slow response,
so we replaced the oxygen sensors and it didn't change a thing same codes keep coming up,
we checked the PVC lines they all look ok and not leaking.
so was wondering if anyone could help.

[undar8ed1]

heater for the o2 sensors not getting power slow to heat up could make a slow response.

[ROBBO_308]

so how would i fix that??