Mercedes: check engine light, rotten egg smell, obd ii

Question
I have a 1997 E420, my check engine light came on and there is now a bit of a stutter during stopping and starting a very strong rotten egg smell from the exhaust, is there possibly onboard diagnostics to check codes as what is on a cadillac or is code diagnosis only something that can be done by a mechanic, and any idea of what this may be from my description?

Answer
Joe,
The Rotton Egg Smell is generally an indication the the Converter is overheating, because of a rich mixture.The condition can get bad enough that a fire could develope from the converter.
Lack of sufficient air in the intake or too much fuel from the injectors can cause this condition.
You need to check the codes from the On Board Diagnostics OBD II. If the vehicle does not have flashing code lites you should be able to get a code reader off EBAY. The code reader should be able to capture and display the code number. These codes are available on the web.
There is a restriction in the exhaust or possibly restriction in the intake or a bad injector causing the problem.
Good Luck
Rob