GM Express Van - Intake Gasket replacement hints and tips

There are a few others out there on this procedure -- but this may well help others with this jenga-like puzzle. If you have abnormally high idle fuel trims on BOTH BANKS, but they come down off-idle (e.g. at 1200 RPM in park warm) and normal or close to it under ordinary driving conditions and have checked the other "easy" stuff (note - a leaking seal on the oil fill or bad PCV valve will do this too; those are easier!) this is very likely the cause. The gaskets are cheap (under $100) and the job only somewhat nasty because its a van. The intake comes out *through the doghouse*, not forward.