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When do I know if I need to adjust my MAF Calibration after adjusting my Primary Open Loop Fueling?

Practical Reflash Tuning

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I'm still a little confused on how do I know if my MAF calibration table is good already? I know that when fueling (AFR) and my afr leaning correction/learning is on point then I should be good. However, how do I know if I need to adjust my Primary Open Loop Fueling or my MAF calibration?

What car/engine is your question for?

Maybe the Primary Open Loop Fueling is a target table and you should use your MAF calibration table to match the first?

“However, how do I know if I need to adjust my Primary Open Loop Fueling or my MAF calibration?”

Log the readings from a wideband O2 sensor when the car is at wide open throttle. Compare the wideband readings to the fuel ratio your computer is commanding. Example - If you are commanding .85 lambda and running ethanol free gasoline, your wideband should read 12.5 AFR (14.7 stoich * .85 commanded lambda) at wide-open throttle.

If you are using the factory airbox odds are your MAF calibration is very good. If the diameter of the tube on an aftermarket intake matches the diameter of the tube on the factory tubing, odds are the calibration is still very good. The OEM spend a lot of R&D on getting this curve as accurate as possible.

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