The flame trap is down below the intake manifold, between the runners for cylinder 3 and 4. It's a bit tough to see but you'll find a big black rubber hose coming off of it. Many people have added a flame trap extension- search for that in the search function of this site. Makes it easier to get at. The parts for it are only $2.50 from FCP Groton.
A tie-wrap will hold on loose vacuum hoses (clamps are usually not small enough. Spraying carb cleaner or WD40 on likely manifold leaks will find leaks- engine running, you'll hear the idle increase.

Airflow meter is the black cylinder on the left front lower fender. It's behind the battery, inboard from the left front strut. It's about 3 inch diameter, about 4 inch long and has big black plastic air bellows hoses going to each end of it. One goes right into the engine intake.
Good luck!
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Rob Bareiss, New London CT ::: 86 244DL, 87 244DL, 88 744GLE, 91 244: 808K total