Hi John,
I didn't actually have this done on mine yet so am not sure how $$ it is -- probably not TOO bad since the rubber parts don't look very pricey, but not sure how long it takes to R and R the intake manifold.

I agree, from your description I would wonder about this. My tech said that the fuel injection system has a lot of lattitude to "correct" things like air leaks so it's possible that the system is trying to compensate for the air leak and thus producing a variable idle ...

Whatever you've got, I think I have the same thing. Has the same pattern, i.e. not being apparent when first stopping at a red light, but showing up some 5 or 10 sec. later.

Hope you get to the bottom of this soon !

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Steve
'93 400E