P0404 and P0405 code?
 

The truck is an 03 6.0L PSD located in the lovely state of Cali4nia. I am the second owner, bought the truck with a little over 150,000 miles on the odometer. The truck is mainly used to tow a roughly 8000 lb trailer behind for short trips around 150 miles. So far, in 5000 miles of towing, I've gotten two CEL's, both when towing up hills. The next morning the CEL was off both times, so I convinced myself 'it was nothing'.

Yesterday I was driving down a mountain road, not towing, just driving, stopped to take a few pictures, turned the truck back on, and the CEL light was on again.

Curious, and I bought an El Cheapo code reader from ebay, plugged it in and retrieved two codes: P0404 and P0405.

P0404 is Exhaust Gas Recirculation Circuit Range/Performance
P0405 is Exhaust Gas RecirculationSensor A Circuit Low

The truck, which is new to me as of March, has not had anything special done to it, save for a nice, expensive oil cooler replacement right after I bought the truck (and started down the long, expensive path of learning known as the 6.0L PSD...)

So, if you can't tell from this write up, I don't know much at all about what I am asking. In fact, I don't even know if I am asking the question right. But I'll try anyway...

What exactly do these codes mean, what is wrong now with the truck, what can be done, and most importantly, for an audio engineer that knows more about quantum physics than diesel repair, how much is it all going to cost?

Sounds like a bad EGR valve - it isn't disconnected is it?

No.

As far as I know, the EGR is not disconnected.

But then, how would I check to be sure it isn't?

p0404 is an egr flow code. the pcm sees its not flowing as requested.
p0405 is a circuit fault basickly controll coil a has filed.
p0405 will give you a p0404 code.
replace the valve. its rather simple. 2 8mm bolts hold it in place its at the top center of the intake right behind the intake air horn (or elbow if you prefer that term)

Thanks to all for your replies!

I've searched the forum for information on how to replace the EGR valve, and even went so far as to open the hood and look for the valve myself.

Just to be sure, this is it, right?

http://frenchy750.smugmug.com/Motorc...00_oPoe6-M.jpg

And to replace it, all I need to do is remove the two 8 mm bolts and wiring harness and drop the new valve in place? Is it really as simple as that? (Somehow I doubt that it is.) I haven't found a detailed procedure for removal, which tells me I am not searching for the right terms. I've read that using a stiff wire brush along with a strong vacuum to clean off any carbon deposits is recommended.

I've found Motorcraft EGR valves (Part Number CX-2056) for around $250 from Auto Parts Warehouse. Is this about the right price? Does this kit generally include a gasket, or does that need to be purchased separately?

Thanks for playing twenty questions with me. If anyone can point me in the right direction, I'd appreciate it!

Not sure about the price or gaskets but I would think new gaskets come with a new EGR--o-rings actually. When you take the bolts out of the EGR you will have to rotate it slightly and it's TOUGH to get out because of the carbon/gunk buildup. A simple trick is to take some strong WIRE and run it through the EGR bolt holes, tie the ends together and use a rod/pole/crowbar to pull up on the loop of wire. The alternator makes a great fulcrun for the end of the bar. It comes out straight up. A lady's foot crowbar also works good to pry it out. Again, it's a pretty tough pull, so get ready.

OH.....yes, that's the critter that you circled.

The wire and crowbar together work great

I've done plenty of reading and youtube video watching, and while it seems like it's going to be a load of aggravation to remove, I am going to attempt to replace my egr valve.

I went on the fordparts.com site to find out exactly what part I need. The site lists two parts with different part numbers; one for trucks that are pre 3/19/2003, and one for trucks that are post 3/19/2003.

http://frenchy750.smugmug.com/Motorc...69_C88zW-S.jpg

I also found this part on ebay, for a lot less money than Ford, but am unsure if it is the right part or not:

http://frenchy750.smugmug.com/Motorc...32_5NKEq-S.jpg

It's a different part number than listed on the Ford site.

So, more questions... How do I know if my truck is pre or post 3/19? And, which is the right part to order?

That's one of those you really need to call the dealership and get the correct number as the valve has been changed and upgraded in design due to operating concerns. This isn't something you can really afford to go cheap on. Those are motorcraft numbers which correspond to a Ford part number. You will probably need the last 8 of your VIN and/or production date to get the correct one.

Thanks!

Getting it done right is more important to me than getting it done cheap (and then getting it done over again.)

Who is a good dealership to call?

After just going down the same road with the p0404 code, I got a new EGR valve replaced under warranty. I'm not sure of the part number, but ford has come out with a "new and improved" EGR valve which is supposedly less susceptible to clogging. It has a pink dot on top. I would recommend if you are going to the trouble to replace it, that you get the newer valve.

Secondly, and probably more importantly, if your EGR valve is coked up, it is likely that your intake and turbo are gunked up as well. While at the dealer, I make a trip back to the service lane and spoke with the tech. He showed me my intake and I was amazed at the sludge inside of it. A nice trip through the steamer and a good hand cleaning of the turbo made a world of difference. If you are good enough at turning wrenches, I would strongly advise cleaning these parts out yourself. Good luck.

Thanks for the tip Hunter. Unfortunately, this truck is way out of warranty.

I'll attempt the EGR valve replacement this week and see just how bad things are. If things are bad (which I am nearly 100% sure they are) I think at that point I will bite the bullet and take the truck in to someone that knows what they are doing for service.

Success
 

For most on this forum, it's no big deal, but for me, it's an accomplishment.

Bought a new EGR valve from a nearby dealership, and with a bit (well, a bit more than a bit) of twisting, wiggling and prying, and of course swearing, I was able to pop the EGR valve out of the truck. Here is what it looked like:

http://frenchy750.smugmug.com/Motorc...44_MiSf4-S.jpg

http://frenchy750.smugmug.com/Motorc...77_buB3Y-S.jpg

It doesn't look too bad to me. The hole the valve came out of had some light carbon around the sides, which I gently scraped off and vacuumed up. The truck was parked on a slight decline, and I didn't notice any liquid down in there.

But even if it's not visible, I know there is a reason for those P0404 and P0405 codes, so rather than trying to clean the valve up, and since I already had the new valve in hand, I dropped the new part in.

The new part from the dealership had the pink dot on the top, which hopefully is the new and improved valve.

Now it is time for the real test, so my wife and I are taking the truck out to our favorite restaurant in the mountains for lunch. The I will plug El Cheapo Reader and hopefully not see P0404 and P0405 again.

Without the help, guidance and encouragement I got from this forum, there is no way I would have attempted this. To all that take the time and share their knowledge to teach guys like me, thank you very much!

You did good.

Often, the fault is electrical (like on my old EGR valve) and a cleaning did nothing to fix it.

A brand new valve from the dealer (never a "reconditioned") is the way to go.

Did you have to clean out a lot of carbon in the plenum?

No, surprisingly, there was very little carbon at all. I was expecting thick deposits, but I only saw a light coating. I gently brushed and scraped it off and vacuumed it out.

Took the truck for a nice run on the highway and up a mountain road, and, at least so far, those dreaded codes have not returned.

Also noticed something that I'd never really paid attention to before. Under normal driving conditions, the temperature gauge barely rises. I'd say that unless towing, it's usually at about the 1/4 mark or less. Today, on the highway before the mountain road, it easily climbed to halfway. Of course, on the way home it behaved the same as always.

Is it related? I doubt it but it was something I noticed that was different. Also, the truck seemed to run a bit smoother than it used to.