I had code 452 and fuel leak whenever filling car. Found that O-ring on pump was bad. Replaced that and fuel does not leak when filling now. But still have code 452. Cleared code and drove around for half hour, and drove it hard quite a bit. Code did not come on. Got back home, shut of car. As soon as I started it, code 452 came back. So it appears code only comes on on restart. Any advice on how to narrow down this problem further. Also notice when changing o-ring on pump that there are three ports on pump. 1. Feed 2. Return 3. Unknown Unknown has a factory line that is about 10" long and forms a u shape. I does not go to anyother line. Is this just maybe a tank overpressure safety setup. It kind of appears that way. Went to dealer and their diagram did not show that line.
