Emission Control Secondary Smog/Air Pump For Audi VW 1998-2006 OEM: 078906601D, 078906601M, 06A959253 PIERBURG: 7.21851.31 HELLA: 721851310 A-1 CARDONE: 332003M OEM secondary air injection pump. Used to lower emissions during cold weather. Common problem on Volkswagen and Audi. Please check the part number before ordering. Fits the following Makes/Models: 2000-2000 Audi A4 B5 1.8T (up to VIN 8D-Y-100 000, ATW engine code) 1997-2000 Audi A4 B5 2.8L V6 30v (up to VIN 8D-Y-100 000) 1998-2000 Audi A6 C5 2.8L V6 30v (up to VIN 4B-Y-120 000) 1999-2004 Audi A6 C5 4.2L V8 2002-2003 Audi S6 C5 2000-2006 Audi TT Mk1 1999-1999 Volkswagen Golf Mk4 2.0L (AEG engine code) 2000-2006 Volkswagen Golf Mk4 1.8T 1999-1999 Volkswagen Jetta Mk4 2.0L (AEG engine code) 2000-2005 Volkswagen Jetta Mk4 1.8T 1998-2000 Volkswagen New Beetle 1.8T 1998-2000 Volkswagen New Beetle 2.0L 1998-2000 Volkswagen Passat B5 V6 (up to prod. 12/1999) In order to avoid return hassle and save yours and our time, you must cross-check indicated reference part numbers against those found on your old unit. Do not rely on vehicles compatibility list, which is presented for the reference purpose and shouldn't be your guide to determine compatibility. If you are unsure, you may call local dealership (auto parts dept.) to obtain correct part numbers or ask your mechanic. If you would like us to help you, please contact us and provide your vehicle's detailed info such as: Make/Model/Year/Engine/Full VIN# and we will do our best to find compatibility.