I have a 94 E420, and the first time my check engine light came on, MB said I needed a new computer also. Evenutally, it was corrected with the wiring harness for free by MB after I learned about these problems through this forum. Check the other threads on shop forum regarding wiring harness, and have MB or an independent inspect your wiring harness. It is a good place to start. I might have replaced the expensive computer also when there was no need. I had about 85,000 miles on the car at the time.
You're right, these moderators know what they are talking about. They helped me too.