most likely its your map sensor. can you get it on a scanner? that will tell you.

 

Please post what you find out, mine does the exact same thing. It will only do it with the trailer on it. I've had the back pressure sensor and tube replaced, the turbo pulled, cleaned and verified it is not sticking. I am planning on getting a scan gauge just haven't thought about it when I have the time.

 

Check your map sensor hose for cracks, it should run from the passengers side valve cover up towards the firewall straight back. If that hose is in good shape I'd replace the map sensor.

 

After reading this thread I went over to Ford and got a new MAP sensor just to try it. $60 and 2 minutes to change are worth a shot if it helps and now I have a spare under the seat in case of an emergency. I'll let you know if it goes into limp mode when towing after this weekend.

 

It seems to have done the trick. I'm able to pull without worry of overboost and going into limp mode again. Thanks PSN!

 

The only thing it says code wise is turbo overboost. I will check but i believe it has a new map sensor and tube cleaned and checked out ok?? Turbo is a new reman from ford 30K ago. Its not sticking. He's getting aggravated with it. Loves the truck just not this crap. He's went and looked and the 6.7's. I really hope not to see one in the driveway. Just now getting mine paid off :doh

 

I haven't pulled the trailer yet but have put a few miles since the new map and it made a difference in the boost pressure for sure. Before, when I left a light it would go to 10 lbs, now it goes to 5 lbs at most but feels like the same power. Engine seems quieter but that could just be me.

DeereMan, my truck also throws the overboost code when it goes into limp mode. I'm hoping the fact that my boost pressure has dropped for normal driving with the new map means I have the problem under control, I'll find out for sure this weekend.

 

What codes are you getting, P0299?? To me it sounds like VGT veins in the turbo are sticking, I have seen it happen a few times. Its not to hard to fix but you have to pull the turbo and take it apart and clean it.

 

Well we finally figured what was going on. And yes some of you were correct. It was the turbo. Come to find out the dealership lied about cleaning it. Nearly everyone one of the veins had something wrong with it. Since its out of warranty its getting the works.(the usual) Thanks for all the replys!!

 

Need to add cetane boost to the fuel and once a week drive it like you stole it to keep the turbo and egr valve clean and working.
2 stroker

 

2 Stroker I don't know if you were talking to me, but it gets ran hard everytime it comes out of the garage. Its only used to pull trailers back and forth to kentucky.
Just to throw it out there we also cleaned the ebp tube and new sensor.

 

I have a 04 6.0 f350 with a fairly new trans when the transmission was installed I had Hercules tune on the ficm I have had the tune off for 6 months now when I reinstalled it my trans is missing shifts going into limp mode

 

In my power stroke it turned out it was an 1157 bulb in the trailer shorting out back in to transmission might be why it happens when you hook up to your trailer