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2003 F250 6.0 P0403 EGR Control Circuit

2051 Views 3 Replies 2 Participants Last post by  ford_doctor
I have an '03 6.0L that I just finished doing some routine maintenance to (Oil, fuel filters, etc.)

First problem: I took the EGR valve off to clean and reinstall, but the bottom half of the valve broke off and was stuck in the engine. By stuck, I mean the packings/soot was holding it in place and I had nothing to grab onto since the top half was completely unattached. Long story short, I got the piece out, bought a new EGR valve, cleaned as much soot as I could and stuck it on there. Hooked everything back up and went on a test drive.
Side note: The soot on the old EGR was more-oily-er than normal.
Real problem: The first minute of the truck running is fine, but then there is a "louder-than-normal" knocking noise and an obvious sound of struggle with a short burst of dark smoke out the exhaust, then clear. While driving there is rough idle, short loss of power, and sometimes like I am getting too much power, and then eventually stalling. Bully Dog tuner gives me a code of P0403 EGR Control Circuit. There is nothing else unusual, no leaks or missing fluids or anything. I did try running it with the EGR valve electrical connector unplugged and it made no difference.

I need any and all advice, honestly. Taking it to a diesel shop tomorrow. Like any average vehicle operator, I want to find the problem and fix it, I don't want to throw a bunch of money at it unless I have to. I have considered deleting it, in hopes of fixing the problem. Mechanic said it'd be about $700, which is fine IF it fixes that issue, but not if there is going to be more repairs following.
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P0403 is a circuit fault. If the concern and the code were not present before you replaced the EGR valve it is suspected that you have a defective new valve. This code if set with other EGR related codes might be caused by carbon getting caught in the valve. You mentioned there was a lot of carbon - unless completely cleaned out loose carbon can find it's way into the valve and cause position sensor codes and driveability concerns like those you mentioned. What did your diesel shop come up with?
I feel like such an idiot. Spent $130 on a diagnostic and it turns out, the pigtail on the electrical harness to the egr valve was messed up. The technician fixed the wiring and the problem is gone. I cleared the codes, so we will see if anything pops up after I drive it a bit.
It happens so don't sweat it. Thankfully the resolution was simple.
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