afr guage reading 7.4 and flashing

[beardyboy]

im using the iniavate lc-1 wideband lambda sensor and has been working perfectly fine on my car, but since last saturday its stopped going up and down in the numbers and is reading 7.4 and flashing even when the car is started or not started, tried to re calabrate it and still hasent changed nothing.

any ideas why please?