So I removed my air box from the car because I dropped my single house key down there between the box and the car. I lost one of the retaining pin to the Bosch connecting pins. Looking at the car from the front, it is bigger pin on the left side on top of the air box. I started my car (2001.5 S4) and all off a sudden my ABS light comes on along with the CEL and the symbol when you turn the traction control off. Also, sometimes on startup, my brake light blinks and chimes. I can't switch tunes and my water/meth doesn't activate (assuming its because if the CEL. Its pulling code P0102.....low MAS circuit volume) I've cleaned the MAS and reinstalled it, cleared the code and it still pulls the same code. Short of buying a new MAS, any suggestions. The only difference is the plug without the retaining clip. Is it really that big of a difference? Car seems to run fine!

 

i assume you mean MAF. the sensor needs to really be in there to accurately make readings.

 

Yes MAF/MAS. I put everything back in the way it was with the exception of the retaining pin. This isn't the first time I've taken the box out, but it is the first time that all this has happened