Mine does not have check engine light come on. The dealer run the code test and found no faulty code. After the problem started, I did replace spark plug, fuel filter, air filter and put fuel injection cleaner in the gas tank. The problem is this is intermittent problem. Could it be ECU or O2 sensor. In JetForeman post, he replaced o2 sensor. Do you think this problem is caused by O2. I check the sparkplud wire, they look o.k. no leakage spark to the engine block. MB dealer told me that if the problem still exist, they suggest to install a ignition booster cost about a couple hundreds. Sine they lost my trust, I do not think this will solve my problem. I already ordered the CD Shop Manual. If you have a solution, please share.