I knew that was next....cuzzzzzzz it's a good question !!!

Couple of ways

Wire colors are:

EGR [Y27]..bk/rd - gy/wt

Air [ y32]..gy/bu - br

There is a pic in the EGR section here:

http://www.peachparts.com/Wikka/M104HeadGasket

..and finally, [ and easiest]..when AIR pump comes ON, see if the EGR vac line is getting Vac..simply pull the line @ egr and put your finger over it to feel the suction.if YES. you know they are reversed .
The AIR SOV is wired to come on WITH AIR pump activation, so if you have vac at EGR w/AIR pump, you know the lines are crossed.

http://www.peachparts.com/shopforum/attachment.php?attachmentid=67045&d=1240263522

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A Dalton