The tube coming up from the lower intake is carrying hot EGR gas, and you want to ensure whichever tube you have here is properly fitting and such. The plastic intakes can warp/fail over time if this isn't done right.
Aftermarket fix (extra work options):
block EGR tube on rear exhaust manifold so this hot air isn't pulled into your intake, and cap or leave open the rear metal flex tube (EGR's not a useful method of emission/mpg improvement anyway)
plug the 2 coolant passages in the lower intake meant to circulate thru the throttle body (freezing open blades aren't an issue, even in Minnesota or further north, and this just provides another leak opportunity)
replace lower intake gaskets with the aluminum ones, if you haven't already (this is the #1 longevity issue on 3800's, and easily fixed)
Guess I never updated you guys on this. Got it all put together, had to trim down the replacement EGR tube as it just barely was too big, nothing 20 seconds with a file and drill couldn't handle. No coolant leak so far and car has been running great, just on the quest of replacing all my emissions stuff that's been ruined by burning coolant haha.
Twice I've had this plastic intake fail because of the heat from this EGR.
Of course hypothetically, if my exhaust & Intake were plugged and the EGR Deleted. Will the computer now make my 3800 run rich or lean, or can I get it tuned to compensate? I can live with an engine light on.
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