2003 mustang chug green cap

  1. M

    Mysterious small green cap and a chugging Stang

    Hello All, First post so please be kind :) I have 2003 Mustang manual transmission with a V6. I was looking for the AC recharge port when I came across this little green cap: I must have messed with it just enough to cause the car to chug violently in first gear. Less so in second and not at...