Nissan Almera emission problems?

My 54 plate 1.8 Nissan Almera has just been for an mot & has failed all of the emissions, meaning no mot until we can find out the problem, the car has covered only 37,000 miles & has been serviced regulary, the car used to cover approx 350 miles a week until March of this year, since then it has only been covering approx 10 miles weekly, we have cleaned the 02 sensor & the maf sensors but still no use also had diagnostic done no fault codes any help anyone please