OK so I have a failure notice from a very friendly Garage in Middlesbrough that passed my 93 WRX even though the following results were found.

First Fast Idle
CO = 10.57% HC = 291 Lambda = 0.73

Second First Fast Idle
CO = 6.38% HC = 299 Lambda = 0.84

Natural CO was fine at 0.35%

Does this mean the Lambda sensor is shot ???
I have seen some reference to this but my figures are much worse than those I have seen. Yes it is guzzling juice as well

Any Ideas ??