Last weekend I cleaned the throttle body on my '95 850 wagon (a.k.a. estate
car). In doing so, I disconnected then reconnected a few items that were in
the way (e.g. air temp sensor cable). After restarting the engine the "Check
Engine" light came on and stayed on whenever the ignition was on. I
rechecked the things I had disturbed. The car seemed to run fine so I made a
mental note to call the mechanic when I got home from vacation. Today and a
few hundred miles later the light went out on its own.

Question: Is it normal for the "Check Engine" light to come on and go off
some days later if you disconnect and reconnect some engine sensors? Any
thing about this that should concern me further?