Hi guys. Can anyone help me? I tried to do MOT's and I had these failures 7.3.D.2c ( exhaust emissions carbon monox. content at idle excessive)... 7.3.2(exhaust emissions carbon monoxidecontent after2nd fast idle excessive)...7.2.D.2b(ex emiss. hydrocarbon content after 2nd fast idle excessive)...7.3.D.2b( exh. emiss. lambda reading after 2nd fast idle outside specified limits) 7.3.A.1c (exh. emits excessive dense blue smoke during acceleration). those from the garage told me it's the EGR valve and oxygen sensor. but after I changed them one day ago, surprise, today the board light reappeared. someone can tell me why????????I must say that after I changed, everything was ok. but today the engine started to stop, and I ended the day with the same light on board, as yesterday. this means money and work for nothing?