I had the same thing happen once after an engine wash. Actually got a "check engine electronics" message along with it. A bunch of water had ended up in the cavities around the spark plugs. If you have a compressor I recommend blowing it out with that. The previous person responding to your post said something about a distributor. If your 97 E410 is the same as mine then it has a coil for each spark plug, I don't think that there is a distributor.