M52/S52 EGR Block-Off Plates (E36)
EGR BLOCK-OFF PLATES FOR M5X/S5X MOTORS! Overview Upgrading your M50/S50US with the M52/S52 headers? Getting rid of your Secondary Air Pump (SAP) and eliminating the EGR system on your M52/S52? These block-off plates are what you need! The EGR system and Secondary Air Pump (SAP) are known to cause headaches especially when building a race car, but simplifying the exhaust can also benefit any car. Deleting the EGR system, decreases complexity, saves weight and does not interfere with the rest of the exhaust or engine management system when done properly (removal of the air pump will require a simulator, reprogramming of the ECU, or a stand-alone engine management system). A common performance upgrade on M50/S50US engines is to replace the headers with the newer M52/S52 manifolds; these EGR block-off plates will be needed to properly install the updated header design. The Secondary Air Pump (SAP) connects to two ports from the head, when it is removed those ports are left open and need t