2003 Audi A4 FSI P1504 Fault Code: Causes and Symptoms Explained
I'm experiencing a P1504 fault code on my 2003 Audi A4 FSI. The car occasionally loses power while driving, then recovers after a few seconds—this can be dangerous if another vehicle is behind me. I'd like to know what causes this specific diagnostic trouble code and how it affects engine performance. Any insights or troubleshooting steps would be greatly appreciated.
A possible cause of P1504 in the 2003 Audi A4 FSI is air leaks in the intake system. This can lead to incorrect air-fuel mixture readings and intermittent power loss.