Mot failure on emissions HELP!!?

Hi happy Easter! I have a renault clio mk1 phase 2, 1.2 on a 1997 R reg. It failed on emissisions as follows.
Fast Idle Fail
CO actual 0.63% Fail
HC actual 108 ppm vol Pass
Lambda actual 1.052 Fail

Second Fast Idle Fail
CO actual 0.71 % vol Fail
HC actual 99 ppm vol Pass
Lambda actual 1.030 Fail

Natural Idle Pass
CO .50% vol

The Limits were
CO < 0.30 %vol
HC < 200 ppm vol
Lambda 0.970 - 1.030

The exhaust system is 6 months old including the cat. I don't drive too fast in low gears but I do short journeys. I had the car running for about half an hour on the motorway before going for the test. Any answers would be appreciated. Cheers Simon