i have a 2000 ml 320 my engine light has been on for about a month, I had the code read at the autozone and it called for a maf.... I cleaned the maf with electric contact cleaner (thanks to another posting[&:]) Now that code is gone, but the engine light is still on and the engine stalls.......... I took it back to autozone and its giving me p0300, p0301,p0303, and p0304 which are all cylinder misfire codes....... the autozone guy says tht these are routine tuneup codes. Is this true and can I just buy plugs and replace them myself? If so how? I've tuned many american cars, but never a mercedes. I just wanna make sure I do it right. Every dealer wants my first born child as a payment! please help