Background:
-New fuel filter
-New fuel injectors
-New fuel pump
All replaced at the Ford dealership.

My truck seems to have an occasional 'miss', and feels like it's running a bit rough. I've noticed it is blowing a little bit more exhaust in the mornings then it used to. Not sure if that is related, but it is something I've noticed.
Still able to make it to the auto part store and work though which is great. I drove home from work today with no radio so i can just listen to the engine and I noticed a small hissing sound that I've never heard before.

Is anyone familiar with this code? I checked my fuel cap and it looks fine.

Thanks.

 

Welcome to the forum

What Year Ranger?

What engine?

 

2005
4.0L SOHC

I look at the filler tube and the lines and didnt see any signs of leakage. I followed the lines from my fuel filter as far as I could see. Is there a way to look near the fuel pump without removing the bed?

 

Mirrors or one of those "flexi-scopes" could help.

I had luck once by attaching a foot long piece of garden hose to the incoming air port on the EVAP system of a car. I blew into it and could hear and locate the hiss.
In my case it was a common weak point in the EVAP hoses.

I do not know where that port is on our vehicles.

 

If you have a helper do this
Open the hood, remove gas cap
Get a short hose and a damp towel/rag

Put hose in filler opening, wrap damp towel around it to seal it
Have helper blow into the hose while you LISTEN for air escaping

Check engine area, since you mentioned hearing a "hissss" there

DO NOT use an air compressor for this, you WILL blow off fittings
Human lungs can generate maybe 2psi air pressure, so can't blow off fittings

 

^ Great idea. I will try that this weekend. Also, my gas cap light suddenly came on while I was on my drive home from work. Can this be as simple as replacing the gas cap? Things never go this easy, especially for me, so I have a hard time believing that.

 

No, the gas cap light is on because the EVAP system has a leak, could possibly be a bad gas cap but not as likely as a leak in a hose, many auto parts store have a gas cap tester

Computer uses the EVAP system to prevent gas fumes from coming out of the tank while driving and gasoline is sloshing around
When you start the engine the computer will use EVAP solenoid to apply engine vacuum to the gas tank, maybe -1psi, not much
There is a pressure sensor on the tank
Computer closes EVAP solenoid and watches the pressure sensor to see if pressure drops fast(gross leak) or slowly(small leak), and it will set a code accordingly
If it holds pressure then no code

The gas cap light is more a reminder that you may have left gas cap off when you filled up, lol, because it wouldn't hold pressure with cap off or if cap was loose.
But you could have a bad gas cap, but usually not a gross(big) leak code for that

 

These trucks are famous for vacuum leaks but people start changing parts before running tests first. Get a smoker or build one like I did hook it up through mass air flow while holding throttle body open. This way you "leak test" the entire system. Having a buddy helps but not necessary