I have a 2.0 2000 GL Beetle and I'm getting the code P1129 from what I believe is the Mass Air Flow Sensor. There are no other codes being generated, so if the problem is not the MAF Sensor, the only other thing I can think of is the air pump. From what I've read the air pump only runs when the engine is cold, or below normal operating temperature. Because there are no other codes I'm at a loss as to where to look for the problem. Anyone have any experience or ideas? Thanks!