For a definitive diagnosis, use a PSA-specific diagnostic tool like . Standard OBD-II scanners may only give the generic code, whereas Diagbox can provide the specific sub-codes (like P306D-22) and live data on throttle position versus air pressure, allowing you to see exactly where the mismatch occurs.
Inspect the wiring harnesses for the throttle body and air sensors for signs of corrosion or damage. p306d peugeot fixed