The 07 5.4 is a 3 valve engine which is a drive by wire. So there shouldn't be a IAC valve on it. I agree that it really can't be diagnosed without more info. But just a shot in the dark I wonder if it could be a bad o2 or a plugged cat.

 

No IAC on the 3 valve engines.

 

So here are the codes from the shop,
P0012, P0300, P0301, P0302, P0303, P0304, P0340

I'm going to try and see what these all mean.

 

i had a similar problem with my truck. started off with randomly dying at low RPM's. Then in reverse. Then it became a very persistant problem. It took a while for a light to finally come on and tell me that my engine was angry. Mechanic said there was a misfire in two cylinders. They did a tune up. Problem solved. Bad spark plugs, bad coil's. If you havn't checked the plugs... you might as well start there.

 

Here's what they mean:

P0300 = Random misfire
P0301-304 = misfire cylinders 1,2,3, and 4.

P0340 = Camshaft Position Sensor Circuit Malfunction

Now here's my thought...the P030X codes are the symptoms, the P0340 may be the problem. Cylinders one through five are on the left side of the engine as you are facing it with the hood open. Meaning you likely have a problem with the CPS on that cylinder head assuming there are independent CPSes for each cam.

From the sounds of it the throttle body cleaning won't do a thing for it.

 

Yes I was referring to the throttle position sensor.

In my case one of the codes I was getting lead me to the TPS, I was fortunate to have another identical TPS to swap on there and figure out the problem, I wasn't suggesting just running out and start buying parts at random and putting them on. I was just trying to keep my story brief and to the point, it's not fun typing a long story on your smartphone while at work.

Redford is correct, no IAC. The computer holds the throttle plate open to what ever it needs for air intake to either start, idle, or obviously for higher rpms. That's why if the TPS is giving an incorrect signal, even just a little bit, it'll drive incorrectly or not idle properly because the computer is then giving incorrect commands to the throttle body assembly. Mine actually got bad enough right before I figured it out that it would go to full throttle at random times while I was driving. That made for a couple scary situations and almost an accident. Not to mention the stalling quite often when I let off the gas.

P0012 = Intake Camshaft Position Timing Over Retarded (Bank 1)
P0300 = Random Misfire Detected
P0301 = Cylinder #1 Misfire Detected
P0302 = Cylinder #2 Misfire Detected
P0303 = Cylinder #3 Misfire Detected
P0304 = Cylinder #4 Misfire Detected
P0340 = Camshaft Position Sensor A Circuit (Bank 1or single sensor)

It's possible the CPS (cam position sensor) is bad. My first thought is have the plugs ever been changed? It's possible the previous owner never changed them for fear of breaking them or if they did maybe they put crap plugs back in. Also I would recommend if you do change the plugs I would put new boots on the coils, I'd bet money they are original and they should be changed when you do plugs.

Curt

 

i agree with curt. start with the plugs. i thought i was having some vacuum problem and some other wild stuff. My mechanic just looked at me and said nope. lets do a tune up. i was doubtful at first. but the next day he called me and said the truck was running like new.... i went ahead and replaced everything from the coils down to the plugs. but at minimum do the boots and plugs.

 

I don't know if the plugs have ever been changed, I'm thinking of getting a new sensor and take it in for a tuneup? I have read some pretty bad stories on the plugs on these motors. What can I expect a dealer to charge for this?

thanks again for all of the replies.

 

Normally I'd agree with you, as good plugs and coils are a must for a good running engine. But two reasons I'm confident this isn't the issue:

1. there is no possible way bad plugs can cause a CPS code.

2. Unless someone replaced only the plugs on the right side of the engine there's no way bad plugs can cause these codes. They are all on the same bank, what kinda coincidence is that? Combine that with the fact that they are on the same bank as the trouble code is indicating...just not possible.

The misfire codes are symptoms, not the problem. Treat the problem not the symptom.

 

so you dont think that constant misfire's on one side of the truck could cause cam shaft positioning issues? thus causing the cps to light up?

 

and if you replace everything from the boots to the plugs, parts will be 80-100 dollars, and labor only took my garage 2 hours. plus they did more by replacing the coils as well. Your mechanic should be able to either visually inspect your coils and say yes or no to replacing them, if not, they should be able to test them to see if they will still generate a spark

 

No I don't, simply because the camshaft motion is caused by two things, which are crankshaft rotation and the orientation of the cam phaser. If that half of the engine is misfiring the camshaft is going to be doing the exact same thing as if that half of the engine is firing normally. Meaning it'll still be connected to the rotating crankshaft and still be under control of the oil pressure activated phasers.

It could be something as simple as a bad CPS, or a short in the wiring to the CPS. Either way you should start there.

 

hopefully it's nothing as serious as you think it may be. im interested to see what happens and the cost of repairs. whats the damage for replacing that censor?

 

Yeah I would start with the CPS first as well. The sensor is about $26 for the motorcraft one at rockauto. It's a fairly easy change. The plugs are not to bad as long as you follow the TSB just in case they are the original ones. If they are the updated design you shouldn't have a problem. It's true the misfire codes could/probably are a symptom of the CPS code however with it being a new to you truck and that many miles there is a chance that there is a misfire problem because of the plugs. Besides it can't hurt to pull one or two plugs and do a visual check.

Curt

 

I agree. the CPS should be replaced, then re-evaluate the engine performance. A bad CPS can easily cause the P30X codes.