[Gregski]

MAF Scaling - Calibration

That's it, that's all you have to do in the VCM Editor to start calibrating your MAF, the rest of the magic happens in the VCM Scanner.

What about Power Enrichment won't that skew our data? Technically we have not enabled Power Enrichment yet, as it comes crippled from the factory on these trucks, for example mine would not kick in until I was above 5,500 RPM (ridiculous I know) on some 6.0L it takes that plus being above 5,500 RPM for like 30 or 60 seconds.

If you enabled your Power Enrichment like I have you can avoid it interfering in other ways, for example, don't go above 5,500 RPM while calibrating your MAF, ha ha, or stay below what ever RPM and or throttle position you set the Power Enrichment to kick in at, so you can take care of it by the way you drive (FYI factory wants you to be above 90% throttle for Power Enrichment to kick in), you can also filter out Power Enrichment mode in the VCM Scanner when you are logging the data, we will be taking this approach. Also technically WOT puts you in Open Loop and we can't tune that with the narrowband O2 sensors anyway, it's just that slight early transition from the end of cruise and into the early start of Power Enrichment that gets skewed.

Another obstacle for us can be DFCO aka Deceleration Fuel Cutoff, this is a feature where when you are cruising and you let off the gas pedal really quickly, the computer shuts off fuel delivery to the engine (why waste fuel right) well this makes the O2 sensors read super lean for a split second and those readings can jack up our MAF calibration, again you can avoid this by not lifting completely off the throttle during MAF calibration, and this too can be filtered out in the VCM Scanner during data logging.

I like the belt and suspenders method, where we try to do both, drive accordingly (no sudden throttle changes, just smooth cruising through as much of the RPM range and load as we can get) during MAF calibration driving and also I like to rely on the filters.