300E Oil Change & Ck Engine Light

Can someone point me to a forum where I can find out what happened. I changed the oil & filter on my 300E and the check engine light went on 5 minutes after I started to drive it. It was not on before the oil change.
You comments would be greatly appreciated.
HiWillis

There is a hard vacuum line that comes off the breather from the crank case to the top of the air cleaner box, this goes down to a rubber elbow then to another hard line that connects to a cylinder in front of the air intake. As the "hard" vacuum lines age they get brittle and can break and obstruct the line, if this has been blocked off or reduced it will set off the "check engine" light. You can disconnect the battery for 5 to 10 minutes (as you probably already know) and this will reset the fault and the engine will go back from static to variable engine control. I don't know if this is your problem, if you find out please let me know.