Ok, got my MS300 scanner from Amazon. It gave me the same codes listed above that I got from Ford, so I erased them Thursday when I got the scanner.

Today:
Unhooked the battery.
Pulled the throttle body off and cleaned it, cleaned the MAF (again).
Pulled COPS #5 & #6 where I was getting the misfires and swapped them with #1 & #2 on the passenger side of the motor.
Pulled the drivers side VCT solenoid out and inspected it. It looked fine, screens intact, no clogs. Cleaned it up and replaced.

Put her all back together and drove her around the block:

Idles good and sounds good while parked. No CEL light on the dash.
In Reverse it idles bad and rumbles till you put it back in drive.
Leaving from a stop it hesitates pretty bad and is still low on power (but runs). Once the rpms come up it cruises nicely but I got some rumble around 50mph till i backed off the throttle and then got back in it.
Randomly it will backfire or pop, but from under the hood, not the tailpipe while you leave from a dead stop.

Got back in the driveway and still no CEL but got a pending code of P0175 (System Too Rich Bank 2).
No more misfire codes.

I also did an I/M Readiness test and got a "not ready" on the following:
CAT = Catalyst Monitor
EVAP = Evaporative System Monitor
O2S = O2 Sensors Monitor
HO2S = O2 Sensor Heater Monitor

Thoughts?

My theory is that it is the fuel injectors??

 

Backfiring through the intake indicates a lean condition usually, but you have an 02 reporting rich along with random misfiring. Thoughts on the matter below.

All of those things make me want to pull the timing cover off and verify the engine hasn't jumped time. You aren't getting any MAF codes, so I wouldn't bother with that. Like O2 sensors, people tend to be quick to jump to conclusions on that. And improper cleaning can damage it.

You can also look for vacuum leaks with propane (safer than carb cleaner, but be cautious). Clean the PCV valve with throttle body cleaner or replace it. Change your fuel filter also.

I'm going to assume this truck is stock. No custom tunes or other modifications.

You can check for a stuck fuel injector with a mechanic's stethoscope and listen to each one.

Finally, buy or rent a compression tester.

What you want to avoid is throwing parts at it. That will get expensive very quickly and may lead you to nowhere.

There are other possibilities (fuel pump module corroded, PCM, wiring or water damage from a previous collision, etc), but take the time to diagnose it. What I've listed above are the things I'd be looking at if the truck were in front of me.

If all else fails, get it to the dealer. They have diagnostic equipment that is far superior compared to what most of us do. I'd love to get my hands on Ford's IDS, but I can't justify spending that kind of money and the online market is flooded with counterfeits.

 

Yes, truck is stock, no tunes. Stock exhaust. Original owner.

No more misfire codes just the pending rich code. Fuel filter was replaced not long ago.

What does the PCV valve do?

 

https://www.f150online.com/forums/20...pcv-valve.html

 

Messed with the truck again yesterday. (It has been sitting in the driveway since it started acting up. Not driving it!)

The PCV valve is in the drivers side valve cover under the power steering pump and by all indications does not come out. It is not the plastic one on the passenger side that I see everyone replacing. So I left it alone.

Visually inspected all of the plastic vacuum lines and their respective elbow connectors. Nothing brittle, cracked or loose.

Took out the fuel injectors on cylinders #5 and #6. (the same ones that gave me misfire codes previously). #5 had a lot of soot built up on the tip of it. #6 looked fine. I used carb cleaner and sprayed them out and cleaned them with a toothbrush to get the carbon off the tip. I don't really know how to check the ohms or check to see if they are "bad" or not. Put them back in.

Started the truck up and it idled decently. No rumbling. No ticking or dieseling. Drove it around the block. No CEL. (Didn't get one last time either). It ran decent at slow speeds. Idles fine at a stop light. Got a backfire under the hood when leaving the stop and it was low on power (like before) but felt a little better. Next light it left with no backfire. Still low on power till rpms came up. (But felt better than before). At 50mph it starts to shake still. But doesn't feel like timing. Feels more like a loose motor mount (although I doubt that is the case, but that is how it feels) then settles down when you take your foot out of the throttle.

No more backfiring at lights, just did it that first time. Still low on power leaving a light. Then runs decent at speed under 50.

Got home. No codes. No CEL. No pending codes. Didn't give me the pending P0175 rich code this time either.

So, still not sure what it is. But every time I mess with it it gets better.

I am thinking about just replacing all of the fuel injectors. Although they looked decent, they may be the culprit. They weren't filled with gook though. Just some dry carbon on the one tip. And super easy to get out. I didn't even depressurize it. Just took the rail loose on the drivers side and popped 5 and 6 out.

Thoughts??

I am honestly ready to trade her in and get something new. But I am patiently waiting on a new job that I am 4 interviews deep into. Hopefully I get it and I can drop by the dealer and get a shiny new something.

 

Anyone??

Over 800 views. I know I am not alone with these symptoms.

 

Hey, I'm back.

Changed the O2 sensor on the drivers side, the fuel filter and trashed the K&N filter and put a new paper air filter on her today and she is running nicely now. No loss of power when leaving a light or accelerating. Ticks when she's cold but it goes away once warned up. She does still idle a little rough but overall sounds and runs good, not great, but WAY better than before. When in P you can hit the pedal and she will come up on rpm nicely now. No stuttering.

I might replace the passenger side O2 sensor just for fun. I tried to get it out and the sensor isn't a problem, but the connector is way up there in a little tight spot I can't seem to get to. Drivers side took about 2 minutes to change.

If I can just get it to idle without the rumbling she should be back to normal.

I wanted to follow up here as I see so many posts where someone has a problem, but never returns to let anyone know how they fixed it. The thread just dies.

 

Ughh, I can't get to the connector for the passenger side O2 sensor. I can wrench the part off with ease but can't get my hand to the connector.

I took off the fender flare and got most of the inner fender well liner out of the way. Even sat with my head in the wheel well but my hand (and I'm not a big guy) won't fit up in that little space.

About the only thing I can see to remove would be the trans filler tube, but I don't think that will make much difference.

She is running really good now, so I might just leave it.

And unfortunately I didn't get that job, so I need to keep her around for a little while longer.