Nissan XTrail Hissing Sound

The symptoms you describe – increased fuel consumption, check engine light, and a hissing sound during acceleration – strongly suggest a leak in your air intake system. Given the mileage (130318 km) on your 2022 XTrail, it's plausible that an intake hose has developed a crack or come loose. Carefully inspect the air intake hoses between the air filter box, throttle body, and intake manifold. Does your XTrail have a turbocharger? If so, check the hoses connected to it as well. Are you able to read the error code from the check engine light?

Yes, my XTrail has a turbocharger. I'll check those hoses. I don't have an error code reader and was hoping to avoid a costly mechanic visit just for that. Is there any other way to pinpoint the leaking area or any method I can use to read the error code without a reader?

While a visual inspection of the hoses is crucial, identifying the precise location of a small leak can be challenging without specialized equipment like a smoke tester. The error code provides valuable insight into the specific issue detected by the engine control unit. Considering the potential impact of an air intake leak on engine performance and fuel economy, and to avoid potential damage, it may be prudent to consult a qualified mechanic for a proper diagnosis and repair. If a simple intake hose is indeed the culprit, the repair shouldn't be excessively expensive. Prepare for a bill of around 100€.

You were spot on! It turned out to be a cracked intake hose. They replaced it, cleared the check engine light, and the hissing sound is gone. Fuel consumption seems to be back to normal. The final bill was indeed around 100€. Thank you so much for your accurate diagnosis and advice!