For my research into MAF information and my CX-5's throttle response and performance anomalies, I determined that a common Wide Open Throttle test commonly used by tuners and technicians provided the most informative data. Specifically, in ForScan, plotting MAF output and total fuel trim over the RPM rise. Then dumping that as a .csv, and into Excel. It was immensely helpful having a very low mileage 2019 Mazda 3, 2.5LNA available to benchmark for normal/nominal MAF and fuel trim response, and then comparing that to the MAF my CX-5 came with, and a number of Ebay and Amazon $30 replacements, rather than popping for $170 Mazda replacement.
The Mazda 3 curve shows that target geometric curve, with
slowly varying fuel trim command of 0 to +6%.
The MAF that came on my CX-5 is next. Notice that the curve is pretty linear, which might seem great, except I know it should be geometric curved! Notice -4 to +9 fuel trim swing, which seems trivial, but the PCM can only swing that 13 points in the span of a several seconds and doesn’t plateau until about 60g/s. The idle trims of -4 means it’s caught flat-footed with an idle launch stumble as the fuel trim is far off of target and the )2 sensor is screaming too lean!
The last plot is the best of the aftermarkets so far; An BAIXINDE unit, that advertises output curve match to OEM of <2% variance. Eh, other than people like me, who has the means or desire to verify that? . While the curve is not as geometric, it’s fits the target curve well enough to keep the fuel trims from idle to 140 g/s in a fairly tight +8 ~ +12 range. That brief trim spike to +16% is probably a data anomaly. Overall good idle launch and light throttle, decent medium throttle with a very slight surging, and good WOT throttle response. I could probably live with this sensor, vs popping for a new $170 Mazda OEM. Anyway, it was a good reason to experiment with ForScan and explore/solve the reason for my CX-5 drivability complaints that did NOT set any codes. [shrug]
Also: the AMAZON 1 sensor produces a SIGNIFICANT reduction of the number of times, the duration and intensity of the Atkinson cycle “waahh” sound.