Anyone have any ideas on this: Have 02 A4 3.0 that was throwing code PO 102. Replaced the MAF sensor with new one from ECS tuning, clear code and now CEL comes on again and shows PO 171 Bank 1 too lean, PO 174 bank 2 too lean and the PO 102 code again, replace MAF sensor. Can anybody troubleshoot what this problem might be?