Recently my 2003 expedition (8 cyl, 5.4L) was runing rough and had two codes registered a day later (P0172 & P0174). I found out what the codes were . I looked under hood and found that my air filter was not connected. I have bought a replacement airfilter, however the air filter assembly (plastic cover) is missing, no longer there. Would anyone know the name and part number of the cover where the filter is housed.