Seat Tarraco Hybrid Engine Issue

I drive a Seat Tarraco as well, though not a hybrid. I had similar symptoms not too long ago. The hissing sound, especially during acceleration, is a telltale sign. Check your vacuum hoses connected to the intake manifold, specifically the ones near the turbocharger. A leak there could definitely cause increased fuel consumption and trigger the check engine light. A faulty throttle body could also cause engine misfire and hissing if air is being sucked in.

Thanks for the quick reply. When you say vacuum hoses, are those the small rubber tubes connected to the intake manifold? And is the turbocharger easy to access? I'm not very mechanically inclined, but I'm willing to take a look before bringing it to a professional.

Yes, those are the rubber tubes. The turbocharger location depends on your specific engine configuration, but it's usually near the exhaust manifold. If you're not comfortable working on it, I'd advise against trying to disassemble anything. A damaged vacuum hose will definitely cause the issues you're experiencing, and can damage the turbocharger in the long run. Your symptoms are pretty clear, so I would recommend taking it to a workshop. They can pressure test the system and pinpoint the leak quickly.

Thank you for your input. It seems you were right on the money. I took it to a workshop, and they confirmed a leak in the intake hose. Repair cost was around 100€. Much appreciated.