07 duramax idle problem
 

my neighbor has a problem when he pus into gear(drive)
the idle jumps slowly up and down. i dont know if this is normal. and he says it just started happening recently.

i know he close to a filter change for the trans.. and that will get taken care of next week.

ideas?
thanks Q

most likely the Fuel Pressure Regulator. Hard to tell with out more info. On mine the idel jumps up and down like you are tapping the go pedal every couple seconds.