If you are using the TwEECer to log, the wiggles in the plots are more than likely due to sampling errors - the TwEECer just misses points or grabs a noisy one or duplicates instead. I have logged the C&L MAF & other parameters using my LM-1 which logs the voltage directly and the curves are smooth and consistent.
With the tuner tube, when I say it samples closer to the middle, I am describing the bend down at the back of the sample tube where is "draws" air in from near the middle of the meter. This "venturi" type pickup makes it more immune to back pulses and it compensates for pressure differentials between the middle and outer perimeter of the meter - making it more immune to irregularities in airflow caused by bends etc in the intake piping.
