Call ford and the BBB, ultimately tell ford you will go to the media. You want it passed inspection and the muffler is after the emissions equipment. Make sure they don't tamper with any government docs because you could be on the hook for that; it is your vehicle you have out on public roads.

 

There are other dealers but this is the one where I bought the truck and it's close to where I work so they run me to work whenever I leave it. It's convenient. But since I've always dealt with them I'm trying to run it as long as I can.

 

Last week I called Ford corporate and the customer care person's initial response was "so what do you want me to do?" After I choked them to death in my head I was able to get them to open a case and they gave me a case number to give to the service manager. They contacted the regional engineer last week trying to get him.

Now my first rejection sticker expired in July. They had the truck at the end of the month and after the reprogram, I thought they were going to put a new one on, but they only did it in "test" mode. I took it down this morning and asked for an updated sticker so the truck is legal. It turned into a tint fiasco since one guy wouldn't inspect it because they said my windshield brow came down too low and the service manager freaked out on someone and another guy tested it. After all that the computer wouldn't print out a new sticker so I still don't have one.

Everybody there is all pissed off now over this so lots of calls were made today from the sounds of it. Ford tech support requested the rear o2's be changed and run the truck while monitoring them. Check all the wiring to the o2's. If nothing is found then change out the PCM. The o2's and PCM have been ordered so as soon as they're in, the truck is going back and they're giving me a loaner car. If nothing is found after that, the regional engineer will be making a visit.

I'm trying to keep this updated because I see this exact problem on some other forums but there's never a resolution posted. So hopefully there will be a positive outcome that doesn't end with fighting over exchanging trucks. One of the advisors said he's never seen this situation in over 30 years.

 

I believe I said it earlier, and I'll double down, I'd put my money on the PCM


Keep fighting the good fight and keep us updated

 

Thanks for updating when the resolution is found as a courtesy.

 

Truck has been scheduled for September 6th to go in for the PCM change.

 

Dropped the truck off early Wednesday morning. They gave me a Fusion as a loaner. The service adviser left me a message that evening just saying they really didn't get to do much since the electrical expert was tied up a lot of the day. I didn't hear anything yesterday so I had a feeling this was going badly. Got a call at 6 tonight and was told the PCM change and re-program didn't do anything. They also changed the downstream o2's. Test drove it and still nothing except now there's no life on the rear o2's either. Before the change there were at least little blips showing up, now they're all reading dead. He said they're going back and forth with Ford tech support again and they're going through the truck looking at wiring and connections. Really they don't have a clue though.

Told them we'll see what happens early next week but I'm pretty much done with this and think we need to get a sales manager and the service manager together and have a conversation about what's realistic here. Not looking like it can be fixed so need to exchange this thing.

 

So I finally cracked open my 2015 Schematic book, hopefully its similar enough to yours.

C139 (connector) has the rear 02 signal circuits passing through it. Its pins 7/8 (B1S2) and 14/15 (B2S2)

C139 is located near the throttle body on the passenger side. Should be able to open both ends of the circuit. (on the PCM and the O2 connectors) and perform a voltage drop test down each wire individually to verify its continuity. A simple Ohm check will not show its ability to carry voltage under a load.



Of course all this is assuming they have verified and tested all PCM powers and grounds.



Just to be clear, on the rear 02 sensors: is the signal side, or the heater side INOP? or both?

 

It sounds to me like it's both sides but I'll try to remember to ask when I talk to them.

 

Both sides are inop. I confirmed yesterday.

I called yesterday to throw in the towel and wanted to start taking some of my aftermarket stuff off but they told me the regional tech would be in on Monday so I'm going to let them do that. They said they had 3 guys on it this past week and didn't turn up anything. If the tech can't find anything then I guess that's it.

 

Just to be clear, on the rear 02 sensors: is the signal side, or the heater side INOP? or both?

You still didn't answer the question. Which part of the sensors is bad, the heater portion or the sensor itself? o2 sensors have an electrical heater circuit in them that heats the detector element to the proper operating temperature. The engine computer controls the power to the heater and monitors the current consumption. If that test fails then the computer will generate an error message usually something like "sensor not ready". OTOH if the sensor passes that test, the computer will measure the O2 detector output and if it is out of range, the computer will generate an entirely different error message. Usually something like "bad o2 sensor" or "sensor out of range". But unless the sensor passes the current draw test first, it will never pass the output level test.

The techs simply saying that the sensor (or sensors) is "INOP" tells me that they don't know what they're doing!

My money is on a bad wiring harness and/or a bad or corroded electrical connector.

 

One other thought. Have these sensors every been replaced? If so did the replacements come from the dealer or somewhere else ????


I had problems with the O2 sensor in a Mitsubishi. At the time, there was dock workers strike going on in So California so Mitsubishi USA couldn't get parts so I bought an aftermarket sensor. The replacement sensor from a local auto parts store and came in a box marked Bosch and was supposed to be a equivalent part but the heater circuit in the replacement sensor burnt out almost immediately (~20 miles of driving). There are a LOT of counterfeit and just plain STTY quality parts out there. I wonder if you might have gotten some bad ones.

OTOH If I was the dealership's tech, replacing the sensors with New OEM sensors would have been the FIRST thing that I would have done. But I've learned the hard way that dealerships usually skip over the obvious in order to cut costs on warranty jobs.

 

The sensors themselves appear to be fine, they're not reading though. They were all replaced with OEM, so I was told. The forward ones were replaced the first time the truck went in a couple months ago. I can't say what the techs have done exactly, I've been told they've gone though all the wiring they can and checked connectors. Turned up nothing.

Today they said they wanted to put the factory exhaust back on. They came to my garage with their parts van and picked up the factory one. Guess there's nothing left to do.

 

Got a call early Thursday morning saying the truck was good to go. They put the factory exhaust on and a tech took it home Wednesday night to run it. Came back in the morning and hooked it up and all monitors showed ready. Said they were going to put a sticker on it but never got a call. Friday morning they said no one would inspect the truck because of the tint brow but it would pass. Whatever, took it to my normal place today and sure enough it did and got a sticker.

Still don't quite understand how the catback caused this. Plan on running the stock setup for a bit but will break down the Roush and reassemble and install to try to duplicate it. Roush tech told me a small exhaust leak could cause the sensors to not show ready but this system should work on the truck. Ford just thought the Roush was too "free flowing" and caused air to rush by the sensors too quickly. Even though the the Roush trucks have the same motor with no modifications and same exhaust. I find it hard to believe my truck is an oddball that can't run it.