Quand je passe la valise de diagnostic sa m affiche aucune communication de la prise obd au calculateur donc impossible de passer le Diag

Hi,
I drive a 2006 Volkswagen Golf 1.9 TDI with around 220,000 km.

Recently, I noticed two issues:

1. A blowing or whistling sound when accelerating and decelerating, which seems to come from underneath the car, possibly around the exhaust line or turbo.
2. A metallic rattling or ticking noise, especially noticeable at low RPMs.
Both noises are more noticeable when the engine is cold, but sometimes persist when hot. I haven’t experienced any significant power loss, and nothing shows up on the diagnostic scan (OBD/valise).
Could this be due to a leak in the exhaust system, a loose or damaged hose, turbo issues, or maybe injectors or valve lifters?

Thanks in advance for your help or similar experiences!

Transmission error light comes on and off intermittently. Connected to OBD, but could not catch codes. Codes do not show up in memory