Engine light just came on

[Gregs X]

I have a 70mm throttle body, stock mass air meter, and a cai. I took it to autozone, and they came up with both banks are running lean PO171 and PO174 They said if both come up, its either a fuel pressure condition or a MAF fault. Does anyone have any advice?
Thanks

 

[chefduane]

Upper intake manifold gaskets. I kept throwing those exact codes for months. Did the mani gaskets and no more codes.

Chef Duane

 

[Gregs X]

is it the upper to lower gasket, or the lower to the cylinder heads

 

[chefduane]

I did both. Got them from Rock Auto for about $12 for the set.
FEL-PRO Part # MS90890

 

[Gregs X]

vacuum leak by the throttle body, sprayed carb cleaner around on a cold engine to find it, all is well now. Thanks