One of the quick connect fuel fittings is leaking where it connects to the fuel rail. This is on a 99 SE. Is there a way to change the fitting or do I have to change the whole line back to the metal fuel line? What is the best way to fix the problem?

Happened to me too, I drained the fuel pressure, took the line off, cleaned it up and put it back on

Already tried that. Helped for a bit but it is leaking again.
Wonder if cleaning the line with emery cloth will help?

It'* not as much the hard line but an O ring in the connector I think

Yes, most freuqently an o-ring fixes it up.

Make sure you add a couple of drops of oil to lubricate so it doesn't tear the O ring inside the female half when you put it back together.

Looking inside the connector I see some white rubber, then a black O ring, then another white rubber piece. Not sure if the white rubber is all one piece. Does all this need to be changed or only the black O ring? How do I get the O ring out without damaging the white piece? Looking a RockAuto, their fuel rail O ring kit looks to only contain black O rings.

Alexm there is two o-rings with a hard white plastic spacer separating them.
Those things a frustrating to replace because the fuel line wants to point down.

I had to modify a dental pick to use to remove the o-rings.

Most auto parts stores carry the viton fuel line o-rings you need.