... from the movie theater, I approached a red stop light, and slowed down. I got to about 20 miles an hour when it turned green, so I accelerated. As soon as I did, the "Check Engine" light came on, and the engine started running like a cylinder wasn't firing. I pulled over, shut off the engine, and waited a few seconds. When I started it back up, it purred as usual, no obvious problems, and performed excellently all the way home. The "Check Engine" light is still on, however. Tomorrow I'm going to pull all the plugs and probably replace them. Is there any way to turn off the "Check Engine" light without taking it to a mechanic and paying them to do it?

Specs on the car - 1997 C280 (arctic white), in immaculate condition, 78k miles on the clock. Bought it last October from it's only owner for $7,800.

 

Likely ECU picked up a (serious) misfire and put engine into "limp home".
System reset (cancelled limp home) with ignition off.
Light (CEL) should go off after a few trips IF the problem ihas self corrected or what an usual set of circumstances but if it came on usually points to something needs attention.

Nwer OBD systems have a memory that is accessible that tells you why the CEL came on. Not available with your model.

Stuart.