bank 2 STFT acting lazy?

[SIXXER]

What could cause for one of the bank's STFT to react slower than the other?

A little background. I made a mistake and spilled a little engine degreaser on my maf. Cleaned it with maf cleaner and everything look ok. No cel and nothing out of ordinary that tell me I messed up my maf. I reset the ecm and monitored my fuel trims. I notice bank 2 STFT reacting about 3 seconds slower than bank 1's instantaneous reaction as soon as I get on throttle. I switched the o2 sensors around thinking bank 2 sensor might be going bad, but same scenario. My AFR look good where it's supposed to be. I don't remember one of the bank reacting slower than the other in the past.

What could be happening here? or is this normal behavior?

[SIXXER]

no one has any idea??