I have a brand new Audi A4 2010 wagon three days old with less than 100 miles on it and the check engine light went on. CarMD generates the OBD II code P2404. That is defined on the web as P2404 Evaporative Emission System Leak Detection Pump Sensor Circuit Range/Performance.

I took the car to the dealer who says it might be a hose leak or the pump needs replacement and he will have to do a dead cold engine test tomorrow. (It is not the gas cap, I checked that first.)

What should I do?

One does not buy a new Audi only to return it immediately to the shop for a few days.

 

give the dealer a chance to make it right. don't let them off the hook until you are satisfied.