Pretty straight forward. Just get your gaskets from GM & be sure to take out the rags you stuff in the heads before putting intake back on.

 

This info has been helpful to me. I have a 2003 Z71 Silverado with the same motor. It is usually garage kept and I am in N Texas. We are having big cold snaps here. I stayed at a friends home in Dallas and the truck stayed outside for the night. When I drove it home my check engine light came on so i ran the code. PO171 on bank one. Today it is still 20 degrees and I have not started it but it seems like I must have to replace my gaskets as well. My friend who owns a repair shop with the same truck said he had the same issue.

Is it difficult to replace them yourself? I have done simple jobs myself but do not consider myself to be a mechanic. I just replaced my spark plugs at 90K with the E plug from JC Whitney. Could this also be an issue? I need to replace my fuel filter again as well.

Do you happen to know of a link on step by step instructions to replace the intake gaskets or should I really have the repair shop do it and not mess with it?

 

I too have a 2002 z71 with the 5.3; at 105,000 I got the rough idle on cold morning (below 30) starts with both P0171 (lean bank 1) and P0174 (lean bank 2) at the same time. Replaced fuel filter, fuel pump and MAF sensor. Now up to about 106,000 and the mornings are getting colder (below 10) Now I'm getting in addition; P0300 (multi-cylinder misfire).

I have sprayed brake cleaner on the intake gasket along with any vacuum fitting I can find and found no leaks. My guess is with both P0171 and P0174 together rules out the intake gaskets since left and right are seprate.

I have noticed that sometimes with the rough idle, which is around 600 RPM almost instantly after starting the engine, once placed into gear the idle smooth out and jumps up to about 1500 RPM. When sitting at idle in park, just the slightest pressure on the pedal will raise the engine to 800 RPM and runs smoothly. I am still getting 17+ MPG in 20 degree weather and the truck runs great everywhere but at idle.

I'm starting to lean towards TPS...any suggestions?

 

I have the same problem as Oliver Man. Same exact problem. Same year truck and same motor. Cant wait to see if anyone has a fix for it.
Thanks.