lambda light on dash

[brownalizat@xxxx]

The lambda light on our dash is lit, what does this mean? We tried 
looking in the owners manual and it was really not very clear. Does 
it mean the car needs to be serviced? Also, my husband was working on 
our '81 delorean and noticed an electronic box below the clutch 
pedal ...what is it? We are new delorean owners and this is probably 
going to be one of many questions that we will have about our lovely 
car!

thanks for your input!