What problems can exist without generating a code?
Starting at 40 mph and accelerating the car begins
to shake. When letting off the gas, it is smooth. It
appears that at about 2000 rpm and accelerating or
going up a hill the engine seems to start chugging.
There was a code for a bad fuel pump but then that
was replaced at the shop. That didn’t solve the
problem. What could cause this and not trigger the
engine light or generate a code?
What kind of code reader are you using? You'll want to connect a BMW specific program like INPA or ISTA to view the BMW-specific codes. If nothing is found, it may be time for an ignition/fuel system refresh. New spark plugs, possibly ignition coils, and run some fuel system cleaner with a full tank of premium.