Date registered: Sep 2006
Vehicle: 83 300CD, 07 ML320 CDI, 04 WRX, 86 300D (totalled by my neighbor), 85 300D (sold)
Location: Columbus, Ohio
Mentioned: 1 Post(s)
Quoted: 45 Post(s)
What exactly does "reset adaptations" do? Is that another fancy word for "reset" the service indicator counter on our ECU. Or is there anything more than that?
Anyway, dont expect to get better fuel milage when the air filter gets replaced (at least not immediately). Right away, your engine will rev much quicker and feel a lot more lively. Modern engines nowadays have MAF sensors. Our CDI has 2 of these connected to the "Y" connector before the turbo. The function of the MAF is to measure the volume of air that goes thru them. When filters are dirty, less air travels thru, the MAF detects that and thus tells the ECU to deliver less fuel. The idea is not to make the mixture too rich due to lack of air. When you replace the filters, more air is detected - so the ECU then allows more fuel dispensed (so that the mixture is not too lean).
Not convinced ? - do this. With your engine warm. Try to download one of those free iphone apps that work like a dynomometer. See how fast it accelerates before and after you replace the filter.
If you feel no difference - reset your transmission computer. I can guarantee your right foot will be very happy. When I did this, my CDI felt a lot lighter than it used to be.