Zeds always run rich, its just the way they are. No filter be it element or cone, will mess with the AFR very much as the car controls it via closed loop (when warm) O2 sensors and MAF. So long as you dont mess with the MAF (and assuming its not duff), the car will control the fuelling to try to achieve its AFR. If you've run the filters for anything more than a day the ECU will have corrected itself and be back on target AFR. Resetting it wont make any difference after a few more days when it once again returns to its target fuelling. UpRev is the only way to sort it properly.
Do a search for the Dyno results thread and you will see what I mean, as most of them have UpRev which is then correcting the AFR for something a little less rich.