Good afternoon to all. I am having a problem with an engine shudder on my 2002 ml 320. As I have seen in related posts , my ml has developed a shudder that is noticable when driving, and most noticable when placing the vehicle in either foward or reverse, and when stepping on the brake, such as when stopped at a traffice signal. I had my mechanic check it out when the check engine light came on and I happened to be near his garage. He hooked up a Snap-On box of some sort (I guess it was some kind of computer or code reader, am I right?) and the OBDII reading showed that there was a misfire in cylinder #2. As it was Friday evening, there was no way he could order a replacement coil, as he suggested the problem could be, but he had platinum spark plugs in stock so he replaced the 2 plugs and told me the new plugs would help smooth the engine out until the coil could be replaced. I must mention he is NOT a strictly M-B mechanic, rather he is an excellant general mechanic who is not brand specific, and who has worked on all my vehicles of various makes throughout the years. Anyway, I believe his diagnosis to be true and I have a few questions. 1. Can I change the coil myself? (I would like to save a few bucks) 2. If I can change the coil by myself, What is the procedure and Where do I get a replacement coil for a decent price? and 3. Which is the #2 cylinder anyway??. Thanks in advance for any and all replys!!!