morning all

my omega, (2.5 petrol), is up the swanny
when it gets warm, as i'm driving the engine management light pops on and goes off again when the car is stopped and engine is idling. done the paper clip test fault codes showing are
87 -- Air con cut off low voltage
135 -- check engine light low voltage
73 -- airflow sensor low voltage
31 -- engine rpm signal or circiut no signal
in that order
now sorry to be a dummy guys but not being an expert on electrics and the warnings comming from different directions, would this  point to one of the above problems having a knock on effect on the others or does this mean something more serious
any advice is much appreciated
thanks in advance
Bob   

thanks hoof

i'll give it a go, i'm a bit confussed though as i only get an engine management light when it gets warm and runs fine when its cold. sorry if i'm being dense.

regards
Bob