Hello all. I have a 1996 C220 with 133k on the clock. My CEL is on and the engine wants to surge when at idle and coming to sudden stops. It sonetimes hits 1200 rpm without touching the gas. Here is what I have done.

(1) I had the local Autozone scan the CEL and they came back with P033 code (which I believe is o2 sensor). Here's the thing. Most things you read is that gas mileage goes way down when o2 is bad and mine has stayed the same (maybe even improved)> I got 29.9 mpg in the city last tank.
(2) Not believing it to be an o2 sensor, I disconnected the battery (5 mins) and cleaned the MAF with MAF cleaner. By cleaning, I mean that I sprayed the jazz in the sensor where I could and sopped it up with cue tips. I couldn't take the sensor off, becuase it had very unique fasteners connecting it (preventing the average JOE from taking apart). It ran beautifully for the first few trips and very slowly got worse and worse and by the 5th day of drivingt he CEL is back on and we are back where we started. Now, I know that the MAF did not get dirty in 5 days. It took 14 years before the first cleaning.

Any help would be great.

 

Have the exact problem on a 95' and have tried everything by my local Benz expert. At 200K, I'm going to put up with it. Interesting approach you took and I'll try your temp solution also. These are 300K engines and remember the germans try to use vacuum/mechanical solutions vs. electronics when they can get by with it. Excellent motor that delivers 29 Hwy and 23 city.