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DEF injectors spray DEF into the SCR catalyst, and have nothing to do with the DPF. A plugged one would only cause NOX levels to shoot up, but again, would have no impact on the DPF. If it was just the opposite and dumped DEF into the exhaust, then it is possible to have wet DEF accumulate in the DPF which will clog it. The injection is just the right amount to turn it to steam to coat the catalyst so it converts the NOX to CO2. You would go through a LOT of DEF in a short amount of time if that were the cause. Do you recall how quickly the DEF went down during your tow?
A DPF is a pipe with tiny tubes running from end to end to catch particulates from the exhaust, what you normally see as black smoke. When it goes into regen, raw fuel is dumped into the exhaust stroke and pumped to the DPF where it raises the temps inside to burn off the soot. There are sensors before and after it to measure the pressure differential to let the computers know how much soot is accumulating.
It is rather simple in function, but rather easy to foul up too if the computer and sensors dont jive, or the raw fuel dumps during regen are not reaching full regen temps. Partial regens could also lead to a fouled DPF by not getting a complete 100% cleaned out DPF.
What did the code say it was when you got the CEL? Did they try to run a manual full regen to purge the DPF?
Sounded more like they were tossing parts it it instead of doing a full diagnostics on it.
Going into a dealer service with knowledge of HOW the system works, even if just the basics as I laid out can go a long way towards actually getting the correct diagnostics done and not just swap out parts they thing are the problem. Thats how this sounds to me.
Awesome explanation and helps a lot. I am wondering now why the dealer didn’t do a manual regen and record the final % blocked or cleared before jumping to a new DPF.
P20EE is a DEF code, has nothing to do with the DPF.
Many times just a NOx sensor, possibly a bad catalyst.
From what I have gathered so far the CEL is really just an indication of an issue with emissions. The error codes are erroneous and guides only. A typical path is DEF quality, fuel quality, DEF injection, Nox 1 sensor, Nox 2 sensor, DPF, CCV, then last EGR. All this can also mess up the turbo, engine, and EGR. Also the part they are ordering that won’t be here until end of March has a revision F at the end. Makes one wonder.
From what I have gathered so far the CEL is really just an indication of an issue with emissions. The error codes are erroneous and guides only. A typical path is DEF quality, fuel quality, DEF injection, Nox 1 sensor, Nox 2 sensor, DPF, CCV, then last EGR. All this can also mess up the turbo, engine, and EGR. Also the part they are ordering that won’t be here until end of March has a revision F at the end. Makes one wonder.
it’s no wonder everyone wants to delete everything off these beasts and let them breathe!
DEF injectors spray DEF into the SCR catalyst, and have nothing to do with the DPF. A plugged one would only cause NOX levels to shoot up, but again, would have no impact on the DPF. If it was just the opposite and dumped DEF into the exhaust, then it is possible to have wet DEF accumulate in the DPF which will clog it. The injection is just the right amount to turn it to steam to coat the catalyst so it converts the NOX to CO2. You would go through a LOT of DEF in a short amount of time if that were the cause. Do you recall how quickly the DEF went down during your tow?
A DPF is a pipe with tiny tubes running from end to end to catch particulates from the exhaust, what you normally see as black smoke. When it goes into regen, raw fuel is dumped into the exhaust stroke and pumped to the DPF where it raises the temps inside to burn off the soot. There are sensors before and after it to measure the pressure differential to let the computers know how much soot is accumulating.
It is rather simple in function, but rather easy to foul up too if the computer and sensors dont jive, or the raw fuel dumps during regen are not reaching full regen temps. Partial regens could also lead to a fouled DPF by not getting a complete 100% cleaned out DPF.
What did the code say it was when you got the CEL? Did they try to run a manual full regen to purge the DPF?
Sounded more like they were tossing parts it it instead of doing a full diagnostics on it.
Going into a dealer service with knowledge of HOW the system works, even if just the basics as I laid out can go a long way towards actually getting the correct diagnostics done and not just swap out parts they thing are the problem. Thats how this sounds to me.
The original code was P20EE before Def injector changed. The new code I don’t have as returned truck when CEL came on. I agree that no manual regen done as there wasn’t time before they announced it needs a DPF. I agree on swapping out parts as their normal course. Personally I just can’t see why a DPF can be defective after 20K miles. Doesn’t make sense.
From what I have gathered so far the CEL is really just an indication of an issue with emissions. The error codes are erroneous and guides only. A typical path is DEF quality, fuel quality, DEF injection, Nox 1 sensor, Nox 2 sensor, DPF, CCV, then last EGR. All this can also mess up the turbo, engine, and EGR. Also the part they are ordering that won’t be here until end of March has a revision F at the end. Makes one wonder.
P20EE isn't about all of that, it just indicates catalyst efficiency below threshold, and the basic causes are few.
Read here> https://www.engine-codes.com/p20ee_ford.html
Bad NOx sensor, bad cat, bad DEF fluid.
There are test procedures to diagnose specifically what is wrong.
so heres the deal. I have had this code since December. This code does not put you in limp mode and the truck can still be driven.
The SCR is bad. The DPF and SCR are one unit so both will be replaced.
There is a load of these due to be shipped out on the 27th with first deliveries on 3/3/23.
Second load is due to be shipped a week or so after with deliveries late March. Absolutely have your service advisor escalte your case so you can get it done.
I would also advise you contact Ford Customer Service to open a case too.
Changing the Sensor and Maybe the EGR are some attempts as well as a new air filter. Also DEF concentration should be looked at too. 33% is the ideal level of concentration.
There are enough people out there whose DPF was mysteriously replaced with a straight exhaust pipe that you should be able to find one with less than 200 miles on it. 🤫
idk what youre talking about, its soaking in a special cleaning solution to make sure i get all the soot outta it.
P20EE is a DEF code, has nothing to do with the DPF.
Many times just a NOx sensor, possibly a bad catalyst.
yes, the first error code was the P20EE and they did replace the DEF injector as it had no output and was clogged. After picking up the truck and driving for a while CEL returned. Made a U turn and back to the dealer. I didn’t get a chance to pull the code. Late today the Serv Advisor said it was a P0420 on the second go around. It is NOT the DPF, rather the the DOC which is faulty. They miss stated as the DPF and DOC are in the same part number and both are replaced at the same time. They did run a manual regen but if it is the DOC then a regen won’t help. Is there any point to replacing the upstream and downstream O2 sensors? Even though now stated as a DOC I can’t see it going defective in 20K miles.
so heres the deal. I have had this code since December. This code does not put you in limp mode and the truck can still be driven.
The SCR is bad. The DPF and SCR are one unit so both will be replaced.
There is a load of these due to be shipped out on the 27th with first deliveries on 3/3/23.
Second load is due to be shipped a week or so after with deliveries late March. Absolutely have your service advisor escalte your case so you can get it done.
I would also advise you contact Ford Customer Service to open a case too.
Changing the Sensor and Maybe the EGR are some attempts as well as a new air filter. Also DEF concentration should be looked at too. 33% is the ideal level of concentration.
great info senix. I have an update posted below. The P20EE was the first code encountered and they replaced the clogged DEF injector. Now saying as of tonight the 2nd code was P0420 which points to the DOC. I have opened a case with Ford Cust Support yesterday and they are working it. I am hoping your dates of the 27th are good ones and that they can pull one for me.
yes, the first error code was the P20EE and they did replace the DEF injector as it had no output and was clogged. After picking up the truck and driving for a while CEL returned. Made a U turn and back to the dealer. I didn’t get a chance to pull the code. Late today the Serv Advisor said it was a P0420 on the second go around. It is NOT the DPF, rather the the DOC which is faulty. They miss stated as the DPF and DOC are in the same part number and both are replaced at the same time. They did run a manual regen but if it is the DOC then a regen won’t help. Is there any point to replacing the upstream and downstream O2 sensors? Even though now stated as a DOC I can’t see it going defective in 20K miles.
Well, I think your P20EE and the P0420 are related, both can indicate a bad catalyst.
They replaced the DEF injector, which probably wasn't necessary, reset the code and then it came back with the P0420 for the same root issue.
Anyway, yes, most likely a bad catalyst, so once replaced should cure the issue.
Passive regens are....well passive (key term). You will NOT know they are happening. Passive regens are said to "happen" with EGTs over 600*F. So towing a car/trailer might put the system into a passive regen.
The active regen message, as popped on the display, was a joke. Literally it lasted like 1.75 seconds....if you didn't see it...well...you didn't see it. That pop up message has long gone away to alert the driver. Ford REALLY didn't do any justice for the owners with that pop up. Either leave it up for 3-5 seconds or not at all. Welcome to the "we aren't going to have a pop up message" regen models.
The best thing you can get to see active regens starting/in-progress is an device like the Insight CTS.
My 2021 F450 with 20K miles tossed a CEL while towing 18K 5th a week ago. Forscan read a P20EE code. Into Ford it went ….. was warned the outcome might not be a good one as they have had other trucks in with the same code and can take a hard path to remedy. First path indicated a change of the DEF injector. Changed. Drove 20 miles and guess what ……. Another CEL. Back to Ford and this time indicated action was a new DPF!! BUT they are back ordered until the end of March. Really. The truck only has 20K miles on it. How can the DPF need replacing. Mechanic said the plugged injector likely caused the DPF to fail. Doesn’t sound right to me. I understand there are hundreds waiting for DPF’s and the back order to clear. Why are so many trucks facing this right now? There has to be another cause. Yes, covered under warranty, (it’s an $8-$10K job) but off the road for 6 weeks is what hurts. Thoughts?
This is not common, but it happens. I saw posts just like this on the Ram forums as well. Luckily I have never had a DEF issue on my rams and hopefully not on the my new F350!
It is frustrating but it can happen with any truck that uses DEF. I would take the risk over DEF issues than have a gasser any day for towing. FCA had a lot of back ordered parts for their DEF systems as well 6-8 months ago - so its a supply issue for everyone. Trust me the DEF and DPF systems today are far more reliable today that when they first hit the market.
