Question

2007 Ford F-550 Super Duty 6.0L with code P0238. Could the EGR cooler cause this high boost pressure?

Answer 1

P0238 Turbo charger boost sensor "A" circuit high

Possible causes MAP sensor, A short to voltage.

EGR cooler cause high boost pressure, Yes it can, So can a faulty MAP sensor it can cause  underboost or a overboost. The way the MAP sensor works it increase voltage as the pressure increases.This allows the PCM to determine engiine boost and fuel demands,The MAP also controls the EGR.What code you have is MAP sensor voltage high this means the signal return or the refernce voltage needs to be look ,being circuit high also means disconnection externally or internally,with the MAP sensor

Answer 2

P0238 FORD - Turbo/Boost Sensor 'A' Circuit High Input

Read more: https://www.autocodes.com/p0238_ford.html