System Too lean, making me go into Limp mode constantly on my 2001.5 A4 1.8T. Thought it was the N75, then a line that was bad, but still doing it. Could it be the MAF? Thanks

you might check your primary 02 sensor....

i just replaced both because they were both bad and i was running terribly lean, replaced the o2 sensor and it was fine. MAF just helped my idle and MAF readings. you might try and log blocks 002 and 115 and see what your airflow readings are...