i've never had to replace a factory intake manifold gasket. reused them several times. not saying that one has never needed to be replaced, but the OEM parts are pretty tough.

 

Now that the weather has finally warmed up here in DFW, the rough cold idle and occasional stalls have disappeared. Cleared the codes on Tuesday and so far they have not come back anymore. No pending codes, either.

Interesting...

 

The P0171 and P0174 codes up north usually occur on higher mileage engines during cold periods. Mine would run fine And idle fine above 20 degrees but with the 24 days of below zero we've had this winter, my truck would die on cold starts and hated to idle. After my intake gaskets were replaced, it idles perfect even at -26 degrees. The OEM gaskets are good, but mine had 167,000 on them and I didn't want to reuse them. I like the felpro gaskets and I'm going to boost mine so it's extra insurance now.

 

I live in the Chicago suburbs and I am having this EXACT problem.

must be my intake gaskets then, because lately its been fine...

 

Yep, it's very common

 

My truck has almost 178K and I highly doubt the gaskets have been changed.

 

Then I would say they are your problem, especially because it went away when it warmed back up.

 

Yep, did the intake gaskets on my 03 up in Alaska at about 170k. It wouldn't idle worth a crap. For what it's worth I never could get it to respond to ether around any of the ports so I never was able to figure out which side/cylinder lifted but the intake gasket fixed it perfect.