First of all, never floor it in 5th or 6th unless you're well into triple digit speeds. That's THE BEST way to destroy the ring lands on your pistons. Read about lspi, as you were very likely doing it to your engine driving it like that.
Second, if you got run off the road, what all was damaged? Intercooler? Charge pipes? What exactly was the code that it threw? The AGS won't throw a code that has anything to do with boost, and it won't set a cel, as there are lots of folks running around without them. Maybe if the connector to the ags motor was disconnected, but I still kinda doubt it.

Sounds like you have a boost leak somewhere, so borrow, buy, or build a boost leak tester and figure out where your boost pressure is going. It's probably a small puncture in a rubber hose or you've got a loose connection somewhere.

Whatever you do, you seriously need to never floor it in 5th or 6th again. That's the best way to destroy one of these engines.

 

“Never floor it in 5th or 6th” got it. doubt there was any lspi going on, damage was intercooler bumper ac condenser and radiator. AGS was never in the car not even when I bought it also the cars center muffler or whatever you call it is gone as well and it has an aftermarket muffler on it, and aftermarket blow off valve. ford dealer might be dishonest I’m not sure but the car is under a warranty that I bought with it it’s isn’t the best one but maybe it will help I’m really just trying to fix it myself because I don’t want to be without the car anymore.

 

The stock turbo spools very fast and makes it's max boost pressure of around 21.5 psi (in overboost mode) below 3500 rpm in stock tune form. At 6500 rpm, the boost pressure has fallen to around 11 psi, as it simply can't flow enough to do any better than that.

When you put your foot down to try to build boost, the computer will start modifying the waste gate settings to do that for you. However, it sounds like you have a leak and it's only able to build 14 psi of boost before the pressure overcomes the hole or slipping connection. So, it will detect that and set an under-boost code and go into "limp mode" .

That mode is there to get you off the road and in such a way that it will hopefully not hurt the car. It only going to 4 psi until you turn the car off and back on again is the way it works.

I don't find it strange that it's only building to a certain pressure and won't go any higher. Ever gotten a tiny hole or screw in a tire? Put 60 psi of air in that tire and it'll blow pressure out quickly, and as pressure decreases, less and less will escape until no more can overcome the rubber pressing around the hole or screw... It still may have 20 psi or more in the tire, right? Same phenomenon as your car building to 14 psi and no further. The computer is demanding more pressure than that, and there's a problem forcing it to not make that mark... Hence, the car goes into limp home mode...

Get a boost leak tester and find the leak. It'll probably be an easy fix for you.

 

The stock turbo spools very fast and makes it's max boost pressure of around 21.5 psi (in overboost mode) below 3500 rpm in stock tune form. At 6500 rpm, the boost pressure has fallen to around 11 psi, as it simply can't flow enough to do any better than that.

When you put your foot down to try to build boost, the computer will start modifying the waste gate settings to do that for you. However, it sounds like you have a leak and it's only able to build 14 psi of boost before the pressure overcomes the hole or slipping connection. So, it will detect that and set an under-boost code and go into "limp mode" .

That mode is there to get you off the road and in such a way that it will hopefully not hurt the car. It only going to 4 psi until you turn the car off and back on again is the way it works.

I don't find it strange that it's only building to a certain pressure and won't go any higher. Ever gotten a tiny hole or screw in a tire? Put 60 psi of air in that tire and it'll blow pressure out quickly, and as pressure decreases, less and less will escape until no more can overcome the rubber pressing around the hole or screw... It still may have 20 psi or more in the tire, right? Same phenomenon as your car building to 14 psi and no further. The computer is demanding more pressure than that, and there's a problem forcing it to not make that mark... Hence, the car goes into limp home mode...

Get a boost leak tester and find the leak. It'll probably be an easy fix for you.

Alright I will get a boost leak tester and fix the problem I will come back and let you know if it works when I get around to trying it. Thanks for the help!

 

What boost does it make in 3rd and 4th starting at 3500rpm?

The stock tune is torque targeted, so the car will make less boost on cold days.

Also as rob stated, never ever floor it below 3000rpm in any gear, or in 5th or 6th unless triple digit speeds.
Also as he stated, boost starts out higher in the midrange RPM then tapers down to a smaller amount by high rpm.

 

The most boost the car has ever showed on the gauge even when I thought it was running right is about 16psi. I built my own boost leak tester and hooked about 20 psi to it and I could hear air flowing but it never held pressure it was like air was going in and then flowing right out. That being said I also forgot to mention that about 3 days after the car went into the ditch I was driving about 45 and swerved for a raccoon in the road all was well after that but before I got home i realized that the turbo spool under acceleration seemed about twice as loud as usual if that helps figure out the problem I’m having.

 

Good job on building your own boost leak tester. So you definitely have a boost leak, now you just need to find it and fix it... Take the panel off the bottom of the car below the engine so you can see the charge pipes, hit it with some pressure, and start poking your head around under there and pushing the pipes around to see if the pitch of the air escaping changes. It may help to drive it onto ramps, too, to give you some room to work.

You'll find it. Let us know how it goes and where the leak is once you determine it.

Good luck!

 

Good job on building your own boost leak tester. So you definitely have a boost leak, now you just need to find it and fix it... Take the panel off the bottom of the car below the engine so you can see the charge pipes, hit it with some pressure, and start poking your head around under there and pushing the pipes around to see if the pitch of the air escaping changes. It may help to drive it onto ramps, too, to give you some room to work.

You'll find it. Let us know how it goes and where the leak is once you determine it.

Good luck!

So I took all the under covers off the car and rolled under and immediately discovered the issue someone had installed a turbo smart blow off valve and the bolts holding it on were all hand tight if not nearly falling off I’d say that probably the cause of the boost leak I tightened the bolts back up and put everything back together and went for a test drive, problem solved I’m building 20ish psi (there’s no way to be sure but the gauge seems to show about right) however the blow off valve was making no noise was pretty concerning to me went back home thinking something was wrong but I noticed a plus and minus symbol on the blow off valve turned it towards the plus about 1 turn and went on another test drive and the car makes a little blow off noise now not as loud as it was but I think that may have been cause the blow off valve was loose also the car doesn’t suck air loudly anymore but I can still here the turbo spool I may go back under the car again and turn the blow off valve up more but tbh the sound isn’t really a big deal to me I like my cars quite. Anyway I’m thinking the problem is solved unless I’m wrong if you could let me know that would be great.

 

Congrats on figuring out the issue and fixing it. Nice job.

Btw, I have a Tial bov on mine and it's very quiet when it releases pressure. Very thankful it's not like an hks bov. Those things are LOUD.