EGRis right before the bend in the air intake that goes over the top of the engine on the passenger side.
ALDA is unlikely, but it's the square thing with the cylinder shaped top on top of the injection pump...
Although it sounds like that air regulator box under the air filter container is more likely to be at fault...

__________________
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Too many people tip toe through life, never attempting or doing anything great, hoping to make it safely to death... Bob Proctor

'95 S320 LWB
'87 300SDL
'04 E500 wagon 4matic