Fleece Performance MAP Sensor Spacer with Boost Reference Port for the L5P Duramax. Problem Because of the direct placement of the MAP sensor into the intake air stream from the factory, soot buildup beccomes an ongoing problem. This requires the sensor to be routinely cleaned or replaced. Solution The Fleece Performance MAP sensor spacer moves the sensor from the direct intake air stream to reduce soot buildup over time and eliminate the need to routinely clean or replace the sensor. The spacer block also integrates a 1 8 in NPT port to allow for installation of an auxilliary intake air pressure gauge. Application Notes Fits 2017 2024 L5P 6.6L Duramax