Start-up RPM Surge

[swl2126]

I have a 2002 2500HD with the 6.0L engine.  I've noticed that if the truck sits for a day or two and I start it, I get a momentary surge in the engine RPMs.  The engine momentarily revs to 1500 RPMs before adjusting to idle speed.

 

Anyone else experiencing this problem?

[CMNTMXR81]

I'd consider it normal.  Probably an errant reading it's picking up from an sensor (primarily the O2's) while in the open loop segment.  Perhaps the cat(s) may not be lighting off fast enough, causing the PCM to either richen it up or increase RPM's to compensate until the cats reach the proper temps.