Car will throw fault code p0401 only after fueling but not everytime. on 1996 Lexus SC300

Changed egr valve vac Modulator and ox senors. I even changed gas cap.

Asked by for the 1996 Lexus SC300
1 answer
THESE CAN BE VERY TRICKY, DID YOU CK PORTS TO SEE IF THEY ARE PLUGGED WHEN EGR WAS OFF. YOU MAY ALSO HAVE A SENSOR ISSUE