ROD AS 2789122 - Caterpillar

Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.Problem
Issues have been reported of engine speed drop and low boost intermittently on the machines listed above. The situations become worse during high speed regen. The EGR differential pressure shows positive at normal condition however, the pressure shows negative during low power. The EGR valve is opened and the intake throttle is closed to increase EGR flow by the engine ECM. It causes low boost until the differential pressure is increased. After disassembling the EGR mixer, it is visible that the port for differential pressure (1) is plugged by carbon.Solution
Check the boost pressure and EGR differential pressure by ET. If EGR differential pressure shows negative during low boost, then inspect the differential pressure port and the EGR mixer and clean if plugged. Illustration 1 shows the location of the parts to inspect.
Illustration 1 g03417542
(1) EGR differential sensor outlet port (2) EGR differential sensor