Yes this is just the engine side, whilst I've got used car warranty I'm happy look at these
I would be careful that it doesn't void the warranty. Just because you can unplug it, doesn't mean that other control modules ( the gearbox especially) won't be logging torque figures and the like. The more advanced cars become, the harder it is becoming to get away with something like this! Almost every module is storing huge amounts of data these days, with some automatically transmitting it back to the manufacturer.
In the USA, GM just got caught selling driving data (speed, acceleration, braking etc) to insurance companies