So I could smell fuel in the cabin when the blower motor was on, and could smell it towards the rear of the engine with hood up. No visible leaks/pooling that I could see, so I replaced the upper and lower intake gaskets, injector o-rings and all went well, ran fine. I could still smell fuel and happened to finally see the leak. Can't get a good photo but it's this piece on the hard line of the fuel rail, leaks out of this "cap". First off, what the heck is it??? Can it be replaced or serviced? Everything I found for part number 4591991AA is no longer available. Even the photos are all one piece on the oem parts site, was it updated.

The photo below is not the same part number but same setup, hard line that can be separated from each injector rail. That round piece circled is where it is leaking....help!!

 

that's the fuel pressure regulator.

 

Really?, I read that the pump, filter, regulator are at the tank. But also can't find that part in microfiche at the tank.

 

the pump has a built in regulator yes this one is for the rail so there is constant pressure in the rail.

 

A little more Googling lead me to Fuel Pressure Dampener. Of course not serviceable, dealer won't sell just that, it's part of the fuel rail that is no longer available. Tried a new 0-ring (same as the injectors) but still seeped. Luckily found a place that had a few of them, $38 later my rust free 2001 Concorde with 71,000 miles isn't headed for the scrap because a computer told the dealer "no". ;-)