Pre-catalyst / Before catalyst O2 sensor.Select sensor location from the menu.Made by Bosch OEM.BMW has now superseded this item with one single Bosch part for both locations.
Part# 11 78 7 523 434 = Before catalyst in front exhaust manifold.
Part# 11 78 7 523 435 = Before catalyst in rear exhaust manifold.
Buyers Note: For models with automatic transmissions only.
Cross Reference:
17215
