No stored data is affected at all. Installing a Muzzler only requires the momentary disconnection of a single sensor, not the whole wiring harness or battery or PCM.I have a technical question about installing the muzzler. When you pull apart the harness to install the muzzler, what data on the van is affected? Are things such as trip A/trip B/mpg reset when this happens? I ask because I am a bit of a fusspot about tracking and comparing the data on the van vs. data I've calculated for mpg, intervals between oil changes, etc.