High speed engine stutter and bog

[tomsTI]

I have 1998 BMW 318ti automatic. The engine stutters or bogs intermitently at high speeds (75mph – 85mph) on the freeway. After reading suggestions on these forums, I have done the following replacements which have helped the issue quite a bit but not solved it completely:

1. Replaced Mass AirFlow Meter
2. Replaced all rubber tubbing and hose clamps from the airbox to the intake
3. Replaced PCV Valve
4. Replaced rubber hose from the PCV Valve to the top of the valve cover gasket
5. Replaced Camshaft Positioning Sensor
6. Replaced Spark Plugs
7. Replaced vacuum hose to the fuel pressure regulator
8. Replaced Catalytic Converter
9. I drive with the ASC deactivated
10. Not related – replaced Alternator
11. Not related – replaced all belts
12. Not related – replaced idle pulley

Any ideas or suggestions?? I’m considering the following but any advice would be greatly appreciated: Throttle Positioning Sensor, Idle Control Regulator, Spark Plug Wires, and Ignition Coil Pack.

Thanks.