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Friday my CEL came on and showed P0401. I cleared it with my SGII but today on the way home it came back on. I do not have a delete kit. I checked my CAC boots and there doesn't seem to be any tears but the one by the turbo has some oil on it. Any thoughts? thanks Rhine.
Have you had the EGR valve out lately? Cleaning it up would be worth a shot. Also pull and clean IAT2 sensor. It's on the passenger side runner of the intake manifold just behind the valve. I'll post a pic of mine if I can find it.
The PCM monitors intake air temp to verify EGR flow by monitoring this sensor and the position of the valve (and probably other stuff). If the valve is gunked up and binding or your sensor looks like this it can be the problem. Also could be simply a failed EGR valve.
Thanks for the help, I got the truck at 77k and it now has 170K and i have never touched either. so it very well could need cleaned. I should have time tomorrow afternoon to clean them both.
Is 3C3Z-9P455-AB still a good part number for the Orings and gasket on the EGR valve?
also for the IAT sensor will i need to change the oring?
one last question, what do i need to torqe them down to when i reinstall. Thank for the help.
You can pick up an O-ring for the sensor just incase the one on there now is toasted.
But most likely is will still be good. Put a little fresh engine oil on it to make it easier
to install.
When I had mine out this last summer with 160 K miles it was still good.
The EGR ones tend to need to be replaced more do to all the soot and it's
abrasive actions from the larger chunks. I have found that I need to do
the EGR O-rings and gasket about every 4th time.
I just looked under the hood, is the IAT2 sensor to the rear of the fuel filter and to the drivers side of the oil filter?
YES. And you will need a 19mm (or 3/4") deep thin wall socket to remove/replace. As far as torque, common sense is all that needs to be used when re-installing.
Thanks for all of the help so far. I took both out tonight and they were both baddly clogged up. Also as I was cleaning out underneth the egr valve with a pick some of the carbon seemed gooie, enough that some of it was sticking to my pick as i pulled it out. Is this a problem????
now for a few pictures.
Thanks again for the help and let me know what you think about the gooie carbon?
In my experience, cleaning out the EGR valve has been a 50/50 success rate for me. In your case however, with only a P0401 but no P1335 to go along with it, you might have a chance. I'll asume that you obtained your code with a device that can only read codes but no live data. If it had landed in my hands, I would've re-installed after cleaning it, and ran what's called an IDS EGR system test. That test would've checked EGR valve position, along with response to various PCM commands while monitoring the other inputs (EBP_A, MAF and MAP etc.).
Given how badly the valve was clogged up, I would be way more concerned about the carbon lodged in the intake manifold more than the carbon on the valve itself. If I were you, I wouldn't stop at the EGR valve. I would vacuum all the rest of the carbon out of the intake as best possible so that you don't have a big chunk break loose and end up jamming an intake valve open as it gets sucked in.
In answer to your question, that gooey carbon is the result of improper/poor combustion, which could be attributed to poor quality fuel with low cetane rating. It would be well advised for you to run some cetane booster additive with your fuel.
In my experience, cleaning out the EGR valve has been a 50/50 success rate for me. In your case however, with only a P0401 but no P1335 to go along with it, you might have a chance. I'll asume that you obtained your code with a device that can only read codes but no live data. If it had landed in my hands, I would've re-installed after cleaning it, and ran what's called an IDS EGR system test. That test would've checked EGR valve position, along with response to various PCM commands while monitoring the other inputs (EBP_A, MAF and MAP etc.).
Given how badly the valve was clogged up, I would be way more concerned about the carbon lodged in the intake manifold more than the carbon on the valve itself. If I were you, I wouldn't stop at the EGR valve. I would vacuum all the rest of the carbon out of the intake as best possible so that you don't have a big chunk break loose and end up jamming an intake valve open as it gets sucked in.
In answer to your question, that gooey carbon is the result of improper/poor combustion, which could be attributed to poor quality fuel with low cetane rating. It would be well advised for you to run some cetane booster additive with your fuel.
I was just using the SGII to pull the code. Thanks for the advice on the cetane booster, I have a couple of the big jugs of diesel Kleen, I'll make a better habit of putting it in every tank. I have been putting it in about every 3.
also You mentioned cleaning out the intake. what is the best way to vaccume it out? thanks for the help again.
One thing you can do is remove the intake elbow and vac from there also.
That heavy duty option would be removing the intake and having it cleaned.
But that is a lot of work.
Well my CEL came back on this afternoon so it looks like I'll just go ahead and put in a new EGR valve. but before i do this I would like to clean underneath it one more time and also clean under the intake and drive for a few days so i dont mess up the new one. To take off the intake elbow is all that is required to take off the black hose and the 4 bolts? is there a gasket under there that i need to replace? Thanks again for the help.