Rougher Idle with air cleaner removed

[GeorgeH]

I have been chasing a rough idle problem with my 1994 SL500 for almost a year now. As recommended by a few folks here, the intake manifold gasket was checked by spraying something non-flammable around the gasket. I noticed that when I removed the air cleaner assembly that the idle of the engine would vary quiet a bit anytime the wind blew. I could even stall the engine by blowing into the air flow sensor. I temporarily replaced the air flow meter and the other one did the same thing. Is this normal behavior? (The throttle body assembly had been replaced about a year ago and I'm wondering if it could be bad.) Thanks!