Just had my Coug on the Fault Code Reader and...NO FAULTS!!!! Nada, zip, nowt, burger all faults, deep joy indeed. However when my friendly mechanic put his machine on "live feed" both lamda sensors were fluctuating cosiderably. Does anyone know of the benchmark readings for these little suckers ?? (may go a long way to explain my poor mpg if they're on their way out, and yes I do drive like a grandad) Many thanks