I I have a 1997 Ford F-150 4.6 L extended cab 3 door. It has almost 270,000 original miles. I am the second owner of the truck, and recently I have replaced many many parts and they include the following: PCM / ECM, fuel pressure regulator, fuel pump, idle air control valve, ignition coil pack both of them, spark plug wires, spark plugs, fuel filter, just recently had an oil change, transmission filter and fluid as well as the transmission pan gasket, coolant flush, brake booster, master cylinder and brake fluid change, both v rear differential and the front differential have just had their fluids changed and the torque converter or transfer case has had fluid added to it. Just the other day I had the cruise control on and when I turned off the cruise control and put my foot on the accelerator it just about died out! It was acting as if it was stumbling on itself and almost completely bogs out. I put it to the floor, and after about three or four seconds it then began acting normal. When the vehicle is in park it feels like a quick Miss every seven or eight seconds. It is throwing codes for the EGR stating insufficient flow, and it is also throwing a code for the idle air control valve saying higher duty than expected. The truck is running but it is running as if it is missing however there are no codes being thrown for a misfire. It's really important that this truck runs efficiently because I am a single father of four, and to say the least I don't have the money for another vehicle right now especially after everything that I've already put into this one does anybody have any suggestions or ideas on how to get this thing running rate

 

I'm sorry I forgot to add that I got gas from a local supermarket and it has only been running this crummy since I put the gas in it. I was going to try and run all the gas out of it and then just put a full tank of hopefully good gas on top of it with a fuel system cleaner and I was hoping that that would clear it up but I haven't gotten that far yet

 

sounds like you have your answer already

 

I would put Drygas additive in to take care of any possible water in the gas from the super market supply.
One of your new coils could be faulty.
What are the codes not just your description?
Spending on all that service does not insure trouble free operation in the future.
Only repair as necessary and save your money.

 

Sounds like you need to clean out the egr passages and verify it's working properly. From what I understand the 4.6s are notorious for plugging up the egr passages. The egr might be the cause of the missing if it's stuck open due to a bunch of crud. # Not a mechanic

 

The EGR passage in the throttle body elbow is probably plugged up. The DPFE might be bad.

It would not hurt to clean the throttle body itself and the IAC valve when you have them off.

With that many miles, a compression test wouldn't hurt, some Techron in the gas should help clean the injectors.

What brand coils, wires, and plugs did you put in?

 

Here is the latest on Christmas day I took the Elmo and the hoses off of the throttle body and EGR and there is what seems to be in my opinion a significant amount of oil. The throttle body as some carbon buildup but nothing that seems to be out of the ordinary. When I did the spark plugs I used auto light the coil packs were motorcraft, the wires were duralast I believe from AutoZone, the fuel filter was motorcraft, and I tried spraying down the intake and the vacuum lines with brake clean to see if there was any change in the idol or anything of the sort and there was not. The truck at higher RPMs seems to run smooth as ice when I go to put it into drive or reverse it clearly is missing or barely running

 

And I apologize but I I am unaware of what the DPFE stand for. What is it, or? And where is it located

 

https://ricksfreeautorepairadvice.co...nd-egr-system/

 

You ignored my reply #4 trying to help you.
What are the codes?
The stalling sounds like the fuel tables are shifted rich from an intake air leak.
This will cause stalling and rough idle but still run ok at speed,
If your Brake Clean is not flammable it will not cause an idle difference, Spraying does not always work especially if the motor is already running Rich.
Shot gunning all over and hoping you get the problems solved is not the way to repair.
If you ignore this reply, then you need some good luck.

 

These engines do not like Autolite plugs, believe it or not. Use Motorcraft plugs and wires. The Duralast wires may or may not be any good, you can get Motorcraft plugs and wires from rockauto.com for a lot less than local parts stores.

Plugs: MOTORCRAFT SP432 Finewire Platinum
Gap: .054
$3.26

Wires: MOTORCRAFT WR5934
$57.89

DPFE: https://www.rockauto.com/en/catalog/...e)+sensor,5088

DPFE hoses: https://www.rockauto.com/en/catalog/...e+/+pipe,10732

Remove the throttle body and the elbow underneath it. Ream out the EGR passage in the elbow, I'm betting that it's completely plugged up with carbon.