Hi,
I think we need to focus on one at a time. If we try to hit all of them, we'll go crazy. So, let's start with the P0102 (mass air flow) code.
If you are certain there are no engine vacuum leaks, follow the directions specific to this in the attachments. The flow chart should point you in the right direction.
Note: I selected the diagnostics to be done with a basic scan tool. If you have access to VAG codes, let me know what they are. I can narrow it down further.
I picked the MAF first simply I feel that if it is fixed, other codes may go away. I realize you replaced the sensor, but there has to be a wiring issue. Following the directions below, you will be confirming power and ground to the maf. I suspect you will find a ground issue.
Let me know what you find.
Joe
See pics below.
Images (Click to make bigger)
Tuesday, April 13th, 2021 AT 6:05 PM