BMW Repair: RPM Issue, camshaft position sensor, mass air flow sensor

Question
Hi Tony, I asked Don this question two days ago from an out dated blog, didn't know he was maxed out with questions, so I pose you this question I have a 98 318TI M44 just replaced my camshaft position sensor because of the engine check light and faults from running a scan. That corrected my rough idle and check light, but the problem I have now is when I go above 2700-3000 RPM the engine and RPM drops down to idle and then picks back up until I go over 2700 rpm again. I did remove the head cover ignition and coil wires before I realized didn't need to for the sensor change all I needed to do was remove the upper intake manifold which I did just unbolted and moved over to get to the senor connector. Also when car is parked and reved up to 2700-3000 rpm does same thing drops out to idle and picks back up could I have a coil going out?????" or vacuum leak or maybe damaged mass air flow sensor from moving intake manifold? everything looks installed correctly. And would a scan help even though no check light has come on? Help

Answer
Hello Leo, a few quick questions,

Did you have this issue before replacing the camshaft sensor?
Was it a genuine sensor or an after market 1?

Have a good look at the "bellows" hose connecting the afm to the intake, they split easily anyway also the hose that connects from the bellows to the idle valve for leaks /splits.

disregard a coil, wrong symptoms,another scan would help as the check engine light will only come on if the emissions are affected.

Check for vacuum leaks first at the hoses mentioned and get back to me.
Also make sure the throttle switch is plugged in properly.

Tony