Intermittent Driving Problem

I have a 2000 323i that has an intermittent driving problem. Sometimes when I start it up I get no SES or other lights and the car drives fine. Other times I start it and the SES and EML lights come on the car drives in limp mode, but is drivable as long as I don't go aver 50 mph. Occasionally, when it goes into limp mode it runs, but it is not drivable. I ran some errands today and about 1 mile from the house the car goes into limp mode where it is not drivable. I turned the engine on and off several times and eventually it went into the drivable limp mode. I arrived at my destination and about an hour later I got back into the car and everything was normal with no drivability issues. I made several more stops and never had an issue the rest of the day. My codes are F6 (Secondary Air System Flow to Low); 44 (Evap System, Purge Control Circuit); A9 (Motorized Throttle (MDK) Final Stage Failure); 6F (Pedal Sensor (PWG) Potentimeter#2); AC (Pedal Sensor (PWG) Short Between Potentimeter) and A6 (I cannot find an explanation of this code). Is there something in these codes that suggest something in particular or a combination of things? Also, does the fact that the codes are intermittent suggest a particular problem that needs attention. Any help would be appreciated.

Intermittent Driving Problem