2000 GMC sierra rough idle when cold

[holschuh11]

I have a 2000 sierra 1500 4.8 v8 and when its cold out my truck will idle really low and then rev up and then back to low idle almost a lope. It has died once it was idling so low. After about 30 seconds and repeating the high idle to low idle multiple times it will eventually even out and idle fine. Its throwing the code P0507. Any help would be apprciated.

 

Thanks!

[O_J_Simpson]

Intake gaskets.