Sounds like major exhaust re-work. Hopefully pre-cats are OK.
Exhaust leak will cause O2 to be confused. PCV should be changed.

 

update:
So I brought the car in to get the exhaust leak fixed. The symptoms I was getting was a rumbling sound, especially on cold starts and when turning right.

What they found is that the bolt that is holding the exhaust manifold was broken in half (half was stuck inside the little hole) and the bolt itself was only on one thread, causing the exhaust pipe to remain loose, causing the engine leak.

The bolt could be taken off with just turning using the hand. Unfortunately, they will need to drill to get the broken part of the bolt out and reattach it which will involve dropping the engine. They will replace the gaskets too, but it may take a day or two to do all the work, unfortunately.


I hope this solves the running lean issue, but needed to get this exhaust issue fixed.

 

I believe it will. It only makes sense. Sucking in extra air before the O2 sensors just confused the system.

 

yeah, it'll take a day or two....like I said they had to take the engine out I guess to get in and drill to get the broken piece of the bolt out. also they saw that there was some oil leak so they're replacing the gaskets around the valve cover not super keen on the exact information. but hopefully it takes care of my issues for a while. thanks for the help, will know more i guess on Monday.

The thing is the dealership and one of the exhaust shops I went to just wanted to replace the entire front and rear catalytic converters, this guy said it wouldn't have mattered since the bolt was broken which was causing the leak.

 

It's hard to find good help these days. I had to change dealers and also go another place before as well. You did the right thing by going to different places. I thought I had an exhaust leak but i didn't. What they did was one guy would block off the mufflers temporarily while the other guy inspected exhaust.
Thanx for sharing.

 

got my car back, fixed exhaust leak, but the light just came on after 60 miles.

back to the drawing board....

 

Did you reset the computer after the exhaust fix by unhooking the negative terminal so the computer could re-learn the changed parameters of the exhaust? If not, do it.
Secondly, check for vaccuum leaks, including accordian intake hose.
P0171 and P0174 lean codes are common faults on many Ford, including the 3.0L Duratec. The lean fuel condition is often caused by a dirty mass airflow sensor, vacuum leaks in the intake manifold or vacuum connections, or a defective DPFE sensor. The fix may require cleaning or replacing the MAF sensor, or using a smoke machine to find elusive vacuum leaks in the intake plumbing. (FROM: http://www.underhoodservice.com/Arti...0l_engine.aspx under Heading Driveability Issues).
When cleaning MAF sensor remove it, spray liberally, and wave your arm around to dry it. Before removing it, remove negative terminal from battery. When MAF is dry, re-install it, then re-hook up battery before starting. Let it idle for 10 minutes before driving. drive it for 1 week.

 

The mechanic was doing the exhaust work. he had to take everything out, disconnected the battery, etc.

I popped the hood, there was a loose hose, maybe it slipped out or something causing a vac leak it was something new. anyone know what this is or where it connects to?

it was sucking in air. what should i do? I'll probably go to the mechanic on Saturday AM..i think this just slipped off. I've checked for vac leaks previously and did not get any but this was probably disconnected recently used carb cleaner. should i cover it with duct tape or something for the time being?



before the exhaust leak, someone did a smoke test, I've cleaned the MAF and I've also checked for vacum leaks with carb cleaner.

 

The reason why I believe that this is not related to this tube (but might be right now) but something else is that whenever I did reset the PCM, it would work for about 60 miles, but then the CEL would come back on after that. It would always come on after starting the car and about 20 seconds after driving the car.

at certain levels of fuel, the CEL would turn off after a few drive cycles, then turn on again, then turn off after 3 cycles....it was kind of predictable when it would shut on and off, which is curious.

 

ok, found where that plugs into. the performance got better than when after the CEL came on...hopefully it is what it is. wonder if the CEL will shut off on its own.