Cannot calibrate the methane sensor its showing OR and when calibration is beginning it show I2C.

Essentially when Solo is in the VP, it uses i2c comms to perform coarse zero when the sensor has drifted. However if it drifts too much then the electronics need a reset. 

First using the front panel, press more until the screen shows the words Diags, press the associated button, and again it should say Z to Mid. Press this and it resets electronics to midscale, then With the lid off, a small potentiometer on the Solo amplifier board, horizontal one. Adjust the zero pot until the display shows zero within 5 ppm. Close the lid, then using zero gas normally perform zero cal on all gases to reset.