P0171 P0174 P0193 P2197 Rough / Surging Idel

[Reklaw]

2004 XLS, 201K Miles. V6, VIN 'K' Flex Fuel.

2 Weeks ago the light comes on and gives me a P0193 Fuel Rail Pressure Sensor A Circuit High. Nothing seems out of the ordinary so I clear it and go on about my buisness. I was a trip coming up so I forgot about it. Then I start out on my trip towing my pop-up camper and 200 miles in the light comes on again. Still running fine so I continue on my trip. At my destination, while checking in I noticed the rough idle and though it was gonna stall so I just shut it off. I run the Ex twice and then don't move it for a week and then when I do and I'm sitting in traffic it's idling rough and I think it's going to stall so I shift to neutral and just keep on the gas so it doesn't stall. I did some searching and can't really find anything relevant other than it could be the fuel filter so I figure 200k, i've put at least 100k of those miles on and never changed the fuel filter so I do that at the campground. Clear the code, drive it a bit with no issues, then eventually the rough idle starts again and now I'm getting the P0171 and P0174 lean codes with the P0193.

Now I think I can hear an air leak. I do some investigating and I find a hose running from the top of the intake to something that is mounted underneath the brake fluid resevori is definitely cracked and leaking. I do some searching it looks like this hose is call a "fuel vapour separater tube" on the ford parts site. Well, of course this hose is unavailable and Rock Auto just lists a generic 25 foot Ford hose. I still can't figure out what that part is that this hose is connected too but I wrapped it up in electrical tape to see if that helps and I headed on the long trip home.

As I was unhitching my camper in my driveway I actually let the Explorer idle and stall out. I just read the codes this morning while I'm at work and now I've got this P2197 "Oxygen Sensor Signal Biased / Stuck Lean Bank 2 Sensor 1" code with all the others.

I'm trying to figure out my process of attack for this. I'm thinking the first thing I should do it take care of the air leaks that I can find. The one I definitely know about is that "Fuel Vapour Separator Tube" Ford part #9D289. But what do I replace it with?

Anyone have any suggestions? Anyone know what that part is that this hose runs to?

 

[Caustic]

Might seem like a waste of time but I'd switch the the sensor to the bank 1 sensor 1 position and see if the code follows the sensor or if it gives the same code after the sensors are moved.