I'm fitting a air fuel ratio gauge just to see if my car is lean or rich but do I run a wire straight from the lamba sensor or from the ecu if it is the ecu what colour is the wire and if it helps my ecu is a 5s thanks 

Afaik Most afr gauges normally run off their own wideband o2 sensor that is fitted into the exhaust or headers .

If it's not broke .....upgrade it 😊