Originally Posted by nhluhr
knowing that it takes at least a couple days for the trims to normalize to where they need to be, you should definitely reset the ECU when cleaning, especially if you plan to be getting tuned the next day, driving hard, track day, etc...
You've just suggested it's a good idea to reset you're ECU the day before it gets tuned or used on a race course. That's bad advice. After you clean the MAF and reset the ECU, the ECU is likely (as in 99.9% of the time) to eventually learn essentially the same long term fuel trim (LTFT) that it had before the MAF cleaning. And the larger the LTFT is in magnitude, the longer the re-learning takes.