I just went through the same routine. In my case, with a '98 E320, 88,000 miles, I noticed that the lights came on in stop and go traffic, when I touched the brakes! I finally realized that the brakes had nothing to do with it, it was the low airflow to the engine when your foot was off the gas pedal. Apparently the MAM sensor sensitivity diminishes over the years and the situation is aggravated at minimum RPM. Slight fluctuations set off the CELs and ENGINE ELECTRONICS lights. Otherwise, our car continued to function perfectly normal. So, it had to be the MAM sensor. (I had even washed it three times, without an improvement.) Last week I bought a new Bosch MAM sensor that fits the 112 engines on eBay from
mbfixers@msn.com for $158, S/H included. It arrived yesterday, I installed it, made several trips and NO MORE warning lights! This guy had 10 units to sell and sold only 6. He may still have some. But I see that you have a C43, is that with the V-8? Bosch makes different adapters for their MAMs for different installations. So be sure to confirm that it will fit.