FIXED Dcop

I drive a 2008 Ford Mustang, V6, convertible, and I have codes P0171/P0174, I have replaced the MAFS, I have 109,000 miles on it. I didn't start having issues with codes until I had some other parts replaced on my car. I had to exchange the MAFS out 3 times, because the aftermarket parts wouldn't work in my car, so I had to buy it from the dealership, and this is when I begin having problems with the engine light staying on with code P0171. When I had the aftermarket MAFS installed, it drove fine for a while, then my car would stall/stop, but it would start back up. After the 2nd aftermarket part was installed, it drove fine, then after a while it begin to do the same thing, and when I tried to give the car some gas, I would press gas pedal to the floor, and it would barely go, and sometimes I just cut off, then it eventually got where it wouldn't start at all. I had to get it towed. After getting the dealership MAFS installed, it sound good, ran good for a while, but now it sounds bad, it runs rough, it doesn't have the power I feel it should have. Can you give me some help on what it may be?

I always like the phrase, " if it ain't broke, don't fix it". This is why I ask, what parts did you replace prior to this problem? and why. This would help to diagnose the problem.

I took it to a repair shop that told me I needed to replace the coil pack, I got a tune- up, I replaced fuel rail injection pressure sensor, front inner and outer tie rods, front loaded complete strut spring assemblies rear shock absborber kit, and MAFS.

The very last thing I replaced was the MAFS, and that was because my engine light didn't go out after he replace my ignition coil pack, then he said it was the code for my MAFS P0171, so I replaced the MAFS with 2 aftermarkets that didn't work in my mustang, so I had to buy it from the Ford dealership, and the engine light and code is still on and showing P0171, and my car is running bad and rough.

What was wrong with the car that had you take it to the repair shop in the first place?

Before the MAFS, it was the ignition coil pack, and I think it was just starting sluggish, so he said I needed the coil pack. Before that, I noticed it was making a noise on the passenger front side, and he said I needed inner and outer tie rods, front loaded struts, rear shock kit.
Yes, I'm a woman that don't know any better but believed him.

Ok... good to know the history. Do you have any means of gathering data? do you have a scantool? In order to determine where the P0171 sets, having freeze frame data to review would help. This would point us in the direction of a vacuum leak or other. The symptoms you describe do mimic a MAF problem. In the mean time, unplug the MAF and run the engine. Does the condition improve?

No means of gathering data, nor do I have a scantool. You want me to remove the MAFS and run the engine? I will do that now.

I thought I had the kind of screwdrewer I needed to remove the MAFS, but I don't have one. I only have a flathead and a phillips.

He’s saying unplug it don’t remove it

I'm a woman that's not familiar with any of that, all I know is that I replaced the MAFS with a Ford dealership part, after diagnostic showed code P0171, engine light still on. I replaced my battery, replaced my MAFS, replaced my ignition coil pack, replaced my inner and outer tie rods, shocks and struts.

Okay, thank you....let me see if I can figure that out....lol!

Does it idle rough or does it bog down when accelerating? Do you hear a hiss under the hood? Sounds like you got a vacuum leak. Kinda guessing with no scanner or anything

I unplugged it and let it run, and it was doing okay at first then it started making a sound, and eventually cut off by itself.

It started sounding rough then it sounded normal, then it started hissing and cut off completely.

I did unplug the MAF and ran the engine, it didn't improve, my car eventually cut completely off.

It's not one's gender that matters in what we do in life, it's the knowledge we obtain and how we use it that does. None of us were born a mechanic, doctor, lawyer ect... we all had to be taught to walk and talk, so never apologize for that.

Do you happen to live in the Denver, CO area? This is a problem a person with limited resources can fix. I would not go back to the shop you used, they do not seem to be interested in fixing your car just taking your money.

No, I don't...I'm in Dallas, Tx. You are correct and I will not be going back to that repair shop.

I wanted to let you know that I found out the problem with my 2008 Mustang that had the P0171 code. After getting a mobile repair shop to come out and do the engine light inspection, I was told by the mechanic, that I had some hidden codes which was P0123, if I'm not mistaken, but it was the new Fuel Rail Pressure Sensor that I recently replaced, it was bad. After I got another one put on, the codes no longer came on, and it runs much better. Thank you.