Check Engine

[sl540i]

Hello To everyone,
I am a new member to this forum and I will like to say that it a pleasure and grateful to be allowed to be part of a community such as this.
I have had by BMW 540i for approx 8 yrs and have spent some money trying to keep it in top shape.
My problem ,however, has always seemed to be finding a good mechanic
Here I am again with a new mechanic(1yr) and I am having a 'check engine' light problem.
The first time I took it for this condition I was told it was the O2 sensors and I also changed the plugs (which was due). I was also told to change the speed sensor which came up in the codes.
For two weeks the car drove like I was accustomed to. perfect. Then one day leaving the office (the car was NOT properly warmed) I tried to accelerate passing another car and the light came on. It has been going off and on after that... always seems to related to accelerating or just after accelerating.
I truly enjoy my car, but I am beginning to loose confidence in its reliability. I love to drive it hard... and sometimes on long trips.
The car started better BEFORE I had the "tuneup"...and I do not detect any improvement in the gas consumption tat I would have expected.
Frustrated.......Porky....

[Teh Prof]

How old is your intake air sensor?

[SpeedInfusion]

wat year and make is ur 540 so i can move this to the appropriate section..