mk2.5 airbag light

Hi

My mk2.5 (2002) 1.6L intermittently has its airbag lights come on.

The red light has 4 long beeps and 8 short beeps
The amber light is on constantly if the issue exists.

The lights arent on everytime i use the car and randomly comes on during a drive, i still have the original steering wheel. My seats have been out & unplugged numerous times.

From my research one post suggests i have disabled(not purposely) the passenger airbag.

Any ideas would be MUCH appreciated as my cars dreaded MOT time is FAST approaching!