Nevadadad

Have had this code on for 10+ months and CEL illuminated. Dealer has checked twice and reset, but comes back on within 1-2 days. Dealer has tested and advised no vacuum leaks found, but I am wondering if a kinked hose (low flow) could be the culprit rather than a leak. Have checked vac hoses in engine compartment and found nothing. Wondering where Leak Detection Pump is on this car...rear driver side wheel well? Don't want to dig there only to find LDP is elsewhere. Dealer said ECU may be faulty but I am not interested in giving them $1700 dollars for something that might fix the problem versus them really understanding root cause.

Any and all ideas welcome on how to diagnose this. Seeing quite a few web hits on p2404 code for A6 when CEL comes on, but few definitive step-by-steps to isolate and rectify. All vac lines in engine compartment seem sound and are not brittle.

Diagram with photo should be helpful. Vac line diagram sticker is on inside of hood, but LDP location and Evap canister non-obvious. Thanks in advance.

milan_o

Do you have a Ross-tech cable to scan?