We have this issue. The car surges and runs horribly. Extreme lean condition. O2 sensors function, checked with adding propane. Good fuel pressure. Disconnect Mass Airflow and it runs great. New MAF runs bad again. On VW, this is how you diag the MAF. Anyone have this problem? Obviously not an injector or ignition problem. I'm starting to thing the ECM is bad.

 

Check your maf wiring harness.

Also check your throttle body. Make sure it opens and closes freely, then clean it with some carb cleaner.

 

We've done that too. Thank you for the advice. Never too experienced to take some good direction. The funny thing is that there's no codes.