Engine computers can easily be reprogrammed to make the engine run at all sorts of different operating bands. You could easily detect state emissions equipment, since it must pull information from the ECU. To me- these devices are either pre-programmed operating modes that produce clean emissions but the vehicle would not operate under this tune (emissions testing is often not under load) and so once back on the road, returns to the original operating mode. OR, entirely fake modules created to trick emissions systems without altering the operating mode.
PS check out Megasquirt if you want to learn about DIY Fuel Injection. I ran a home brew Megasquirt/Megaspark system off an IBM laptop in my Volvo 740 Turbo back in the 90s, one of the things that got me into hardware.
PS check out Megasquirt if you want to learn about DIY Fuel Injection. I ran a home brew Megasquirt/Megaspark system off an IBM laptop in my Volvo 740 Turbo back in the 90s, one of the things that got me into hardware.