HIGH/LOW IDLE - RPM Variation

[red-red-red-red]

This week my 6.0 has stated varying a couple hundred RMP up or down at low idle (pretty rapid), once at higher constant rpm there is no fluctuation. I am not reading any codes and my SCT livewire isn't showing anything abnormal.

Please help.

 

[Derkperk]

How does it idle with the stock tune?

 

[red-red-red-red]

Good question - I haven't switched back to check. I'll let you know.

Thanks

 

[red-red-red-red]

Did it worse on stock tune - IPR valve