Pierburg Mass Airflow sensor for the Mk4 ALH Jetta TDI, Golf TDI and New Beetle TDI.
Years ago a popular replacement option for the failure prone Bosch MAF was a replacement unit from Pierburg. The Pierburg MAF featured a back side heat sink that helped prevent the over-heating problem that caused Bosch MAF failure. They also were, thankfully, cheaper than the Bosch units since the element was available without buying an entire new housing.
As a bonus, the Pierburg MAFs were largely considered to be a better performing MAF. Owners reported better responsiveness and better power throughout the RPM range. While not a “power upgrade”, many owners to this day swear by their Pierburg MAF units.
