story:
In case one has a flash-EPROM in his ECU one can reprogram that EPROM just through the OBDII connection

so that would be easy and one could first save the original EPROM parameters and make the tuning thereby reversible...

question:
does our Tib have a flash-EPROM???

that's what www.powerchipgroup.com says:

Datasheets

Your Hyundai Tiburon 2.0 4cyl uses an ECU which features an embedded processor rather than a normal chip or EPROM which means that your car does not use a chip that can be modified. The Powerchip upgrade for your car is an additional computer which alters the ignition timing of the vehicle in the same way as a normal chip style upgrade. Installation takes about 1 hour and can be performed by a Powerchip Authorised Fitter. We have authorized fitters in most areas. Please enquire at the time of order for your nearest fitting station.

In standard form, the Tiburon 2.0 4cyl produces 102 kW and 181 Nm.

Powerchip has a range of chips to suit your car, which can increase it's power to between 112 kW and 115 kW, and it's torque to between 200 Nm and 204 Nm.

I think you just answered your own question!

-Scott

ok I found out that DIL-Eproms are rewriteable and PLCC-Eproms are not-rewriteable