Tiburon Hissing on Acceleration

Sounds familiar! I had a similar issue with my Tiburon. The hissing sound when accelerating is a major clue. It definitely points towards an air leak somewhere in the intake system. Have you checked the intake hose for any cracks or disconnections? That's usually the first place to look. Also, give the intake manifold a once-over. Leaks can be tricky to spot, but that hissing sound means there's a decent-sized escape somewhere.

Thanks! Where exactly is this hose located and how can I check it?

Right, so the intake hose runs from the air filter box to the throttle body or, if you have one, the turbocharger inlet. It's usually a corrugated rubber or plastic hose. To check it, visually inspect the entire length for any visible cracks, splits, or damage. Also, feel around the hose while the engine is running (carefully!) to see if you can feel any air escaping. If you're not comfortable doing this yourself, I'd recommend taking it to a workshop. A smoke test can pinpoint even the smallest leaks.

Thanks a million, I took your advice and brought it to a local mechanic. Turns out it was exactly what you said: a leaking intake hose. Cost me 100€ to replace. Now she runs like new!