Tuning is a process of making adjustments to optimize the performance of an engine....
A Tuner Device is an electronic device that hacks the software/hardware of a modern vehicle, to allow changes that you normally can't make....
There is a difference, but since you have to hack the vehicles computers to "Tune" it, using a Tuner Device, they add extra features into that tuner device to do some additional hacking that enthusiasts buying the device might want to do....
So no amount of tuning, as in making adjustments to the engine, will change the results of a test of the Catalytic Converter....
But using a Tuner Device to hack the vehicle computers, if it has the features, could be used to turn off or disable the test of the Catalytic Converter....
BTW, adding to the confusion, most modern vehicles use a Speed-Density System that utilizes Experimentally Derived Data from a test engine as reference for values (or adjustments) to operate the engine, but still correct for variances and wear between engines.... ....so the makers of a Tuning Device could "Tune" a test motor and develop that experimental data to just load into your PCM....
People doing real "Tuning" are taking their vehicle to a speed shop with a rolling dyno, spending a week there "Tuning" their engine by making fine adjustments to operating parameters to get every bit of power possible out of the engine....
But people are also using "Tuner Devices" to hack the vehicle computers to load data into their vehicles for a more optimized engine profile, they call this tuning, it's a stretch but not wrong either.... ...using computers to control the engine allows you to transfer the adjustments from one engine to another via the computers...
They also refer to these Data Sets that are loaded as "Tunes", stretching it a little more, but it's not wrong......
If you didn't know what tuning was, you'd get the misconception any kind or hacking or modifying the vehicle was "Tuning" it....
In the old days, as an engine wore, you periodically had make measurements and adjustments (i.e. tune) to compensate for the wear and keep it performing optimally... ...the old Tune-Up... ...this was done when spark plugs and filters were changed, because eroded away spark plugs and dirty filters throw off the performance and adjustments of the vehicles.... ....modern engines with computers and sensors tune themselves (different than performance tuning).... ...so a tune up is no longer necessary, but they still need spark plugs and filters changed, so Dealerships will pray upon people's ignorance and charge twice as much for a spark plug and filter change, telling them its a "Tune-Up" when they is no tuning they do, the engine computer is doing the tuning several times a second as you drive...
And finally, if you're changing the engine operating parameters with a Tuner Device, keep in mind, if the OEM could make the engine more powerful by changing the data in the computers they would have done so.... ...there are three reasons the OEM's have the engines power reduced below their full potential....
- Emissions - the engine has to pass emissions and that emissions equipment has to last, at least 85k miles, so operating engine at different parameters that might make more power would cause it to produce to much pollution, or burn up its emissions equipment, like burn up or clog your Catalytic Converters... ...but you don't have to worry about emissions in South Africa, and you're removing your Catalytic Converters, so no worry in that regard for you....
- Safety/Reliability - most vehicle owners and drivers are idiots that don't understand the first thing about how their engine works, they will not recognize problems with the engine and even knowing their is a problem, will continue to drive with the problem.... ....the OEM's build in a safety factor in the operating parameter of the engine, so the engine is not operating right at the edge of envelope so that inattention or neglectfulness from the owner doesn't result in the engine melting down....
- Longevity/Reliability - the OEM tests these engines thoroughly, fully instrumented and torn down and all parts inspected with each change in operating parameters.... ...so the OEM's already know that the 25 extra HP you can get from a little tweak to a certain parameter actually results in a rise in temps of the exhaust valves that result in halving the life of those exhaust valves..... ....the candle that burns brightest is also the candle that burns the shortest.... ...the motor makes a much power as it can safely for hundreds of thousands of miles....
No, upping power a bit with a Tuner Device is not inviting disaster, but just keep in mind race cars have their engines tuned to extract every bit of power they can make, and every other race you see one of those motor explode.... ....so you don't want to go too crazy changing your motors operating parameters, and you need to be vigilant on watching that motor and catching any malfunction...