Lemme guess - made by the same company that Volkswagen used to cheat before their diesel lawsuit?I used to have no cats and headers on a car and just had this little box that I hooked to the 02 sensors and battery and it told the cpu that the 02 sensors were working properly. Had that thing on there for like 10yrs. Couldn't tell you what the name of it was because it came with the headers haha. They were Stillen.