Chip tuning

Modern electronic control units can be tuned by simply updating their software through a standard interface, such as On Board Diagnostics.

Most manufacturers tune for optimum emissions (running rich to protect the catalytic converter) and fuel economy purposes which can limit performance.

A poorly tuned electronic control unit can result in decreased performance, driveability, and may even cause engine damage.

The most common way to "upgrade" the electronic control unit is using either plug in modules as mentioned above or using a specialist tuner who will use an Onboard Diagnostics Flash tool.

This is a well known fact to the manufacturers of such misleading devices, so all of them will have phantom tracks which appear to start at the OBD connector and go into the PCB, but they either will be left unconnected or be connected to a microcontroller, which will not utilize the pin for anything.

Such devices rely on the fact actual products exist which can be used to change the programming of the ECU and these reprogramming methods are not a plug in solution.