surging 6.0

[missingsc331]

Here lately i have been noticing that my truck, when at idle, the turbo seems to spool and then cut out ... i also notice it when i am driving slow. i just recently changed my exhaust to dual pipes just in front of the back tire with no cat or muffler so its significantly louder and i may not have noticed it before ... is this normal or could this be a sensor or what ... thanks

 

[atk]

it is normal....what it does is cycle the variable vanes in the turbo to keep them from sticking do to extended idling....far as i know, most 6.0L trucks have this programming...hope this helps...