P0131 P0132 P0135 (and fuel backup when filling)- 2003 Ford Windstar

To start off - I’m a DIYer and don’t have access to scan tools or a smoke machine and I’m trying to diagnose an issue in my wife’s minivan. I do have a test light, multimeter, a harbor freight OBD2 code reader, a handheld vacuum pump with gauge (mityvac), and some common sense (I think). Thank you in advance to anyone who can offer some advice.

“Customer (wife) complaint”: When filling at the gas station, gas frequently rises back up the fill tube and spills on the ground. Once this happens, we must fill the van extremely slowly to avoid the gas spillage. I have experienced this myself, it is consistent and extremely annnoying. Sometimes I can get a half a tank in before it happens, but never more than that. To be clear, I care more about stopping the fuel backing up and spilling than fixing the trouble codes, but I would like to fix both if possible.

Trouble Codes: 
P0131 - Lack of HO2S11 switches - Sensor Indicates Lean
P0132 - O2 Circuit High Voltage (Bank 1, Sensor 1)
P1132- Lack of HO2S11 Switches (Sensor Indicates Rich)
P0135 - O2 Heater Circuit (Bank 1, Sensor 1)

(My code reader has freeze frame data for only the P0131 code: 
Fuel Sys 1: CL - Fault
Fuel Sys 2: N/A
Calc Load: 34.1%
ECT: 82 degreees (F)
STFT B1: -3.9%
LTFT B1: 0%
STFT B2: -3.9%
LTFT B2: 0%
Engine RPM: 1550)


My understanding is that the O2 heater circuit is tied into the EVAP system and I’m thinking maybe the codes and the gas spewing symptoms are related?

Testing done so far - Today I started to look into the problem but only got so far before my 2 year old had other plans. I disconnected the lines from the charcoal canister and vent solenoid and blew into them, and they seemed fine. I did notice a few ounces of liquid fuel had accumulated in the charcoal canister based on it spilling out when I disconnected the line between the vent solenoid and the charcoal canister. At the very least the line from the canister to the gas cap does not seem clogged. I tested the EVAP purge solenoid in the engine bay (key on engine off) and had 12v in both wires at the purge solenoid (ground side switched?) I then disconnected the harness and applied power and ground to the solenoid to see if I could hear the solenoid activate. I could not hear or feel the solenoid at all and I tried reversing polarity as well, still nothing. Should I hear anything from the purge valve solenoid? I also (with engine running) pulled the EVAP line that connects from the purge solenoid to the intake and I could tell a vacuum was being pulled. Engine temporarily ran very poorly when I pulled that line and returned to normal when the line was replaced.

Is my purge solenoid bad based on lack of noise when testing or do I need to test with the vacuum pump to verify? If my purge solenoid is bad, would that cause the gas spewing issues with this vehicle? Or am I likely looking at two separate issues? 

If anyone can recommend any testing I can do at home with my basic DIY diagnostic kit, I would greatly appreciate it. I definitely plan to repeat the testing I did to the purge solenoid on the vent solenoid as well. I will probably also quickly check powers and grounds to the B1S1 O2 but my thoughts are that this is more EVAP related than it would be an O2 sensor. 

Hey WoodsTruck! IMO, you're chasing two separate problems. The O2 codes are likely unrelated to your refueling problem Since the refueling problem is the real complaint, we can chase that first.

The liquid fuel you found in the charcoal canister is usually a red flag for the canister. But, there's a couple tests you can do. The easiest one would be to simply disconnect both hoses from the charcoal canister and try to fill the tank again. If the tank now fills, the problem is in the canister, vent solenoid or the vent path to atmosphere. If the tank still doesn't fill, the problem is in the tank or one of the several hoses it uses to vent air out of the tank.

If the tank fills normally and you want to take it a step further, you can then reconnect the hose that goes from the fuel tank to the canister. Leave the hose than vents to atmosphere disconnected. If the tank still fills normally, the problem is in the vent hose. If the tank stops filling again, the problem is in the canister.

The purge valve won't cause this issue, as it's a normally closed solenoid and not intended to be a vent path for the tank during refueling. The fact that you didn't hear or feel the purge valve opening when you were manually energizing it could be a problem, but isn't THE problem. Circle back to the purge valve later.

Dunno if attachments are working these days, but Ford TSB 03-7-7 suggests doing basically the same thing as I described above.

Tyler, thank you for the reply and some direction on how to troubleshoot. I will go and attempt to fill up with the lines disconnected today or tomorrow.

I have one question to make sure I’m following 100% - I am seeing three lines going to the charcoal canister:

1- One line off the vent solenoid (forward side of charcoal canister) that runs up towards the front of the vehicle. This one has a connector that I push in on both sides and can remove
2- A similar line but on the rear side of the charcoal canister. This line also has the same connector style as the one off the vent solenoid. I believe this is the one that goes to the tank.
3- a third line with no connector, just a friction fit over a nipple. It attaches to a smaller rectangular box off of the charcoal canister. I believe the smaller box is a filter of some sort for the canister? If I’m remembering it right, this is the line that goes up towards the filler neck.

Can you confirm which of the three lines mentioned that should be disconnected? Hopefully I explained myself well. If not I can get some pictures for you later today.

Update: I did a bit more investigating today and wanted to share my findings so far. I have not tried filling up at the gas station yet with the hoses removed but will try tomorrow and report back.

-There are 4 hoses total that I could locate near the charcoal canister, two towards the front of the van and two towards the rear. The two towards the front both conenct to the vent solenoid. One towards the rear (with a push-to-release connector) looks like it connects directly to the charcoal canister, and the other connects to the smaller rectangular filter before then continuing into the charcoal canister.

-I did some loaded circuit voltage tests at the vent solenoid with the connector plugged in and KOEO. There is a purple/white wire and a red/yellow wire. I used a test light as well as a multimeter. I was getting battery voltage on both wires, but one of the wires (i believe it was the purple/white wire) made the test light glow much brighter.

-I also removed the vent solenoid connector and did a resistance test across the two pins of the vent solenoid and got a reading of ~60 ohms.

-With the vent solenoid removed from the vehicle, I applied power and  ground from a spare charged 12v battery I have laying around. I could not gear any type of sound or feel any type of movement when doing this. I also did an in-line amperage measurement with my multimeter while applying power and ground to the solenoid, and got a reading of around 3-3.5 Amps. This seems very high to me, but I don't know for sure. My guess with what I have tested so far is that the vent solenoid is shorted out internally. It also seems like it initially got stuck due to charcoal pellets getting stuck in the solenoid. A bunch fell out when i removed it and i can hear more rattling around in there. 

-I also noticed some damage to the wires just before the vent solenoid connector (picture attached). I actually thought the wire was green instead of purple/white until I pulled some tape off the wiring harness to do my testing. I am wondering if this could be part of the problem, or maybe a symptom of the solenoid shorting out?

My main questions at this point are:
-Should I hear or feel the vent solenoid actuating with power applied? My thoughts are my testing so far show it is bad (or at least clogged and unable to move).
-Does anyone have a diagram of the evap system for this vehicle so i can wrap my head around which hoses go to where?