Hi Towbarman25, It may not actually be the boost pressure sensor itself. On many CAT ACERT engines a boost code is usually caused by so****ing upstream throwing the readings off. Since you’ve already replaced the sensor, start by checking the wiring and connectors for corrosion or rub-through, as these engines are notorious for harness issues that trigger the same fault even with new parts. Also inspect the charge-air system for leaks, including CAC boots, clamps, and the cooler itself, because any intake leak can cause rough running and false boost values. If the engine has a VGT, make sure the turbo actuator is moving freely and that it’s hitting its commanded positions. Low fuel pressure can also mimic air-related problems, so confirm both supply and transfer pressures are within spec. And because you had a bad voltage regulator, double-check the ECM grounds and power stability—voltage problems can cause multiple sensors to read out of range. The Snap-On scanner is helpful, but CAT ET will give you the deeper data like desired vs. actual boost and fuel timing corrections, which can point you in the right direction. Overall, it’s likely not the new sensor but so****ing causing it to read wrong, so wiring and leaks are the best places to start.
