I completely changed the original stainless steel pipe from my intercooler to the plenum today, (had tee-piece welded into the new pipe for dump valve, and the charge temp gauge fitted with a proper locking fitting).
To cut a long story short, when i used to boot the car with the old pipe on the air/fuel ratio meter would only show the first led of rich illuminated! With the new pipe fitted both the rich leds light fully at full throttle! Conclusion...air leak on one of the rubber hose connections!
All sorted now though and the car is running alot better as well