I have a 95 C-280 with 170k and the same problems as described on your 96---idle "hunting" and cutting out and misfiring during acceleration. I have had the engine wiring harness, EGR valve, plugs (not platinum) and ignition wires replaced. Still suffering with the same symptoms. Most recently a tech found and repaired 2 vacuum leaks...did not solve problem. I had the MAF replaced but when the techs found it did not cure the problem they removed the new MAF and re-installed the old one at my request. We have spent a bunch of $$ trying to fix this and am running out of patience (and money). Any other suggestions?

p.s. there was evidence of mice chewing wires and vacuum hoses. The tech said to put whole cloves under the hood, in the trunk and under floor mats. He says the smell of the cloves irritates the rodents and will repel them.