Well first thing to do is pull the codes. That will get you in the ball park, then you gotta decipher the codes.

Ok, check this out. I am not going to attempt to make a homemade code reader or whatever so I take the car to my mechanic and his diagnostic computer just locked up and would not give a reading at all.

He had to take the car to another shop and their machine worked, but it came back with 25 codes! It's like a friggin' bingo scorecard.

P0116, P0170, P0101, B1100, B1234, B1419, B1422, B1424, B1220, B1221, B1010, B1000, B1203, B1012, B1014, B1021, B1124, B1438, B1436, B1214, B1119, B1200, B1470, B1231 and B1232.

Now either my car is dead and doesn't know it or one of my computers is messed up. Anyway, I took my friends advice (confirmed by the Mercedes dealer believe it or not!) and simply unplugged my battery and replaced the OG air cleaner system and wala-no more CEL and no need to buy a $300 mass air flow sensor or anything else-for now.

This lead me to think about a few other things. When I bought this car in Japan I had to change out the instrument cluster (km to mph) in order to conform to CA DOT; could that have caused some electronic gremlins in the car? And, I am also wondering if these Mercedes systems are so sensitive that DIY maintenance is just not possible without having to "reset" the electronic brains that control the whole car everytime you change a sparkplug!?

Any advice out there to a newbie owner who likes to work on his cars, but is scared to mess with this one anymore. Cheers. Hiroshi.