Hello all, my car failed the MOT last week on a small piece of welding .The garage had to remove the petrol tank to do the weld as it was very close to the hole,they also fitting me a new rocker cover gasget.It passed the MOT but shortly after I picked the car up about a mile towards home the engine management light came on for about 10 seconds then went off,i have driven the car about 15 times since then and each time after about amile or so the lights comes on for about 5 to 10 seconds the car is also running a bit rough ,and also a bit shaky whiles idling at 900 revs went the car is warm .I have driven the car for 9 years and the light has never been on before and the car was running fine before it went in the garage.I took it back to the garage and they charge me to run some test and told me it was contamination of the lamder sensor because my car is burning a little oil,they cleaned the sensor for me and told me it should be OK but its not.Are they pulling the wool over my eyes as the was running fine before they had it for the MOT repairs.Has anybody an idea what it coulld be ? It a 1994 Peugeot 106, 1.4 XSI ,UK car IT DONE 120,000 miles and has a full service history. Thankyou ,regards Martyn.