X10 - Noisy Pictures after Sensor replacement

Since my Fuji x10 sensor was replaced to address ORBS issues, I find most pictures taken in M size and those in EXR mode (Hi-Iso/Low Noise or DR Priority) reults in very GRAINY pictures.

Other posts in this  forum indicate that Fuji recalled such cameras for further adjustment after the sensor change.

Does anyone know what is tweaked when the sensor is changed?  I believe it is some software / firmware specific to the sensor or lens or something else.  Since I am unable to send my camera back to the States, I want to go to a local Fuji service center and ask them to check/update the specific firmware.  Appreciate any feedback.  Thank you