I just discovered what may be a serious problem, It started a couple of days ago as a tremble and some hesitation when put in gear; however it has escalated to the exhaust pipe connection between the engine and the Catalytic glows red hot. ( this is not normal )[:@]

 

Yikes. Have a qualified mech. take a look right away. SOunds a little like a plugged catalytic conv, but that is juct a WAG. Don't wait, see a good benz shop.