Norwell Gallery BMW is being very difficult. Have 2001 X5 that was in under warranty several times for SES light. reset and told to tighten fuel cap...yeh right. Now I take it in with 55k on car and they say that camshaft position sensor bad, negative lead on airmass sensor bad along with a few other minor issues. BMW North America is useless in that they are tangled up with getting their marketing team to review situation and force dealer to help. Is the camshaft sensor repaceable by individual with good common sense but no special tools? I replaced airmass sensor but still pops the negative lead code. Any thoughts?