Ford Super Duty (1999-2016) :: 2004 F250 V10 - Stalling Out - OD Light Flashing

I have an 04 F250 4x4 king ranch with a 6.8 V10.

When I first bought this truck it had a problem of stalling out at stops. You could sometimes hold the brake and gas and push your way through it but it would sputter for a second and try to die and then it was fine once you got going. The OD light would flash, check engine light would come on and it would throw a P0720 code for the OSS. I did some researching and I pulled the sensor in the pumpkin before that because I read that could cause the same problem, so I cleaned it and put it back but it didn't solve the issue. Then found that an K&N air filter can often times clog the MAF and cause the issue so I pulled my air filter and sure enough it was a K&N, I swapped it with a normal filter and sprayed some MAF cleaner and its been running like a top for months... until now.

It started again, gradually at first. It would die when I started to back the truck at a very low speed to load my 4 wheeler. I fired it up and it was good again for a couple more weeks, then I went to hook to a horse trailer and I was having to back up a hill to get to it, and it just kept dying, OD light would flash, check engine light came on. I was in a bind so I just tried wiping off the MAF with a rag, that didn't work, my girlfriend was using the truck and said it kept dying whenever she stopped. I got it home and cleaned the MAF with cleaner really well but the problem persisted. I went ahead and changed my oil, spark plugs(gaped at .052-.054), replaced the IAC(which looked like it had been installed once before so I am guessing someone tried it and when it didn't fix the problem they returned it) and changed the fuel filter. I drove it around and it ran fine, drove it to work and it ran fine, my girlfriend took it for about 15 minutes to run an errand for me and it was fine until she got back in the parking lot and liked to never got it parked again it stalled so much.

So I went back to the drawing board and read that it is rarely the OSS that is the problem but that often times the issue is a bad coil pack. I don't have a scanner nor do I know how the heck to use one. I plan on going out of town at the end of the week and the truck has 194k miles on it so rather then take it to a shop and try to find out which COP was bad I just decided to replace all of them(I know, I know, you should never just start replacing parts). I only had time to replace 5 of them, I took the truck out and again it dove fine for an hour, went through traffic OK. It sat for an hour and when I left it started to die again, I could drop it in neutral and it would fire back up and as long as I gave it just a hair of throttle it stayed running fine, take my foot off the fuel and in a minute it would die again. After I drove for a bit it was fine again. Now I know the problem may yet be in the remaining 5 COP that I must change tonight but in case it is not I wanted to get input on this.

I've read the problem can come from a bad ground, so I took every ground point that I could find under the hood and I cleaned the connectors and took the paint off at the connection site just for good measure. The problem persists. I've read that sometimes a diode can go out on the alternator and cause this problem, I did use my amp meter and I'm checking out at 13 volts while running. I'm not the best with meters so I'm not sure how else to check the diode?

I've also read that taking it to a dealership is hit or miss for them diagnosing the problem, sometimes they find the issue, sometimes they just change the OSS. The only mechanic I trust closed his shop and is now service manager of the Dodge dealership. I'm thinking since this seems to be a common problem that maybe ford might have more knowledge of it then dodge but I trust the dodge dealership more because of who is over it. Either way I know it will sit in a dealership for awhile before it ever gets looked at and if they have to chase any electrical problems then that starts racking up $$ fast.

So what am I missing? I've thought about replacing the MAF since cleaning it the first time solved the problem. When it did this the first time I still had my 01 F250(it never gave me problems like this) and so I took the MAF off of it and swapped them and sure enough it fixed my problem so I switched them back after I cleaned the MAF and like I said it's been running fine until recently. I'd rather not throw money at this by replacing parts and hoping for the best. I've also read about tracing the harness that runs from the sensor on the pumpkin to the OSS and on. That harness runs through all kinds of stuff so I'm dreading that but it will also be a next step. I haven't pulled the OSS because its in a very awkward position on my truck.