Thicker intake gaskets
Some(me included) are of the mind that better air bubble evacuation results from using them.
Others (GM included) feel they are not needed/worth the cost (Here's where GM opted out lol).
It probably works as well either way. To me it's just more efficient to use them, as a better cooling system results, but that's just me.
The causes are:
-Dirty or faulty MAF
-Vacuum leak (manifold O-ring??)
-Fuel system problem (rail, injectors, pump, regulator)
So now that we have the correct code, you know what could be it. And the manifold seal IS one possibility! Try a test where you spray WD40 around the ports to see if it does anything. Any leak will become evident.





