Have had this c200k 2002 model for three days and though have hardly driven it as it was bought for resale,have noticed that engine management light is now on. took to a local indy who said that fault codes were for a air mass sensor and for oxygen sensors. have changed air mass sensor but still getting engine management light on and now when i check with diagnostic machine am getting a p0138 code...o2 sensor bank 1 . The car in it self drives well,power is ok,but am now a little worried as have looked on forum and noticed that these c200k engines are a little prone to faults.People have mentioned oil getting into loom and air mass hence light on.By the way the air mass i put in was an 80pound job from car spares . Is there anything that i can do as some have suggested that fault lies in wrong air mass choice and others that to fix this i need to clean intercooler,breather pipes, . Very confused as car runs well but engine light a big put off.