Cummins ISX VGT hunting

[Rawze]

(05-31-2024 )alamow Wrote:  I had a simular experance and found the exhaust pressure sensore tube was blocked.

Checking for a blocked up exhaust sensor circuit is decent advice... however, even with a blocked exhaust sensor, it still should not be 'hunting' like that whatsoever after a proper de-mandate.

The turbo should have been properly re-programmed and the engine operating mode logic changed so that the turbo does not want to spool up to begin with. It should not be hunting for any positions, and any spooling up of the turbo at idle is a sign that the engine is still trying to warm up an aftertreatment can that no longer exists.