Diesel Dawgs…Please Help Me Troubleshoot

Sludgemonkey44 · 2026-10-26T09:36:07-0500

Hey Tremor Family,

I’m writing this to see if anyone can help me figure out what is going wrong with my truck. I just got home from my annual trip to North Dakota for waterfowl hunting and I noticed a bit of an issue with my DEF system. I’ve taken this trip several times while towing the same trailer and I’ve always been able to make the round trip on a full tank of DEF. Well this time I had to stop and throw a box at it on the way home and it’s already doing the 500 mile countdown to empty since I’ve gotten home. Also, I noticed a powdery residue on the inside of my exhaust pipes that I’ve never seen before. I was making temps high enough for a passive regen on the way out and back, so I thought maybe it was DPF dust, but it’s very white and when combined with the excess DEF consumption I’m thinking it’s burnt unused DEF crystals.

So the little bit of research I did pointed me towards a bad DEF injector. Now all of the bad ones I see online look like they are leaking/corroded/something off looking with them. I looked at mine, and it looks nothing like any of the “bad” ones I’ve seen online.

So at this point I’m reaching out to all of you smart folks on here to see if anyone else has run into anything similar and if so, what was the problem/ solution? And yes, I’m sure someone will say “just delete it” and solve the problem completely. And yes, that is a potential solution, but I’d like to know what all of my options are before making any decisions moving forward. Also, seemed to tow fine power wise, no codes, normal fuel usage, not smoking, etc. Just seeing if anyone can help me figure it out before I have to pay someone to help.

Thanks in advance!

Edit: Forgot to add if it matters…2020 6.7 Powerstroke and I just rolled past 100k miles on the way home.

NightForceFan · 2026-10-26T09:43:41-0500

I am no help here, just chiming in to let you know you still have the best color ever offered from Ford.
Hope you come to a resolution on your situation.

Vecman · 2026-10-26T10:30:30-0500

Time to get rid of that entire system, especially since you hit the 100k mark. That would be the best choice for you. Don’t waste time trouble shooting, just get the tune and be done.

donmatteo · 2026-10-26T10:39:01-0500

For sure a def injector.

Sludgemonkey44 · 2026-10-26T10:57:28-0500

donmatteo said:
For sure a def injector.

Any chance you could elaborate a little? I read somewhere about possibly pulling/soaking/replacing original, or better off just buy a new one a swap it? Any chance it could be something else? I appreciate the response, but it’s lacking detail unfortunately.

securityguy · 2026-10-26T11:04:07-0500

Time to do a full delete and call it a day!

The Evil Twin · 2026-10-26T11:20:10-0500

I’d wager the injector is hanging open. If you are going to pull it and attempt to clean it, I’d just put a new one in. Granted, they are like $450 , but what’s your time worth. And you might end up having to put a new one in anyway.

donmatteo · 2026-10-26T11:28:57-0500

Sludgemonkey44 said:
Any chance you could elaborate a little? I read somewhere about possibly pulling/soaking/replacing original, or better off just buy a new one a swap it? Any chance it could be something else? I appreciate the response, but it’s lacking detail unfortunately.

Evil twin responded for before I could.

It's stuck open so it's best to just replace it.

Sludgemonkey44 · 2026-10-26T11:32:12-0500

Much appreciated boys! I’ll make a phone call and see if my local ship has one in stock.

DTX2023Tremor · 2026-10-26T11:34:02-0500

Or you could trade it in and get one with a 7.3L engine. I hear those are really reliable

I'll see myself out now before the rotten fruit and veggies start getting hurled my way.

donmatteo · 2026-10-26T11:45:00-0500

DTX2023Tremor said:
Or you could trade it in and get one with a 7.3L engine. I hear those are really reliable

I'll see myself out now before the rotten fruit and veggies start getting hurled my way.

SHUT YOUR WHORE MOUTH WITH THAT NONSENSE

NEOHIO · 2026-10-26T11:45:27-0500

DTX2023Tremor said:
Or you could trade it in and get one with a 7.3L engine. I hear those are really reliable

I'll see myself out now before the rotten fruit and veggies start getting hurled my way.

Hmmm.... Didn't your truck just undergo a heart transplant?

donmatteo · 2026-10-26T11:48:28-0500

Sludgemonkey44 said:
Much appreciated boys! I’ll make a phone call and see if my local ship has one in stock.

QQ - how old was that DEF in your tank? What DEF do you use?

FWIW - I know DEF is DEF however I've seen some batches go crystal before. My 2022 would go months without needed it and I elected to have it cleaned as part of the service one time and they said it was mostly junked up.

I'm kinda happy my 2025 drinks it like a drunken sailor in port in Thailand.

NEOHIO · 2026-10-26T12:13:28-0500

Sludgemonkey44 said:
Much appreciated boys! I’ll make a phone call and see if my local ship has one in stock.

Are you on FB?
Maybe see if you can find some parts that fell off a truck. Might be cheaper than throwing parts at it.

Sludgemonkey44 · 2026-10-26T13:04:09-0500

donmatteo said:
QQ - how old was that DEF in your tank? What DEF do you use?

FWIW - I know DEF is DEF however I've seen some batches go crystal before. My 2022 would go months without needed it and I elected to have it cleaned as part of the service one time and they said it was mostly junked up.

I'm kinda happy my 2025 drinks it like a drunken sailor in port in Thailand.

DEF was fresh from a truck stop pump on the way out, and i honestly didn’t look at the expiration on the box I bought I threw at it on the way home. It sucked down half a tank in 1200 miles. I normally get well over 5000 on a tank even with a substantial amount of towing included. I’m not thinking it was the DEF. It was almost certainly something malfunctioning in my DEF system.

Sludgemonkey44 · 2026-10-26T13:07:40-0500

And to all of you who say hey just delete it. Yeah like I said in my original post, it’s an opinion that I have considered. I’ve also considered the fact that by deleting, I’m lowering the resale value, shrinking the potential future buyer pool, and therefore making it more difficult to sell for a decent price when I do decide to finally part ways with it. Not to mention I don’t love the noise and stink associated with the loss of the DPF. I definitely have a love hate relationship with the entire system.

donmatteo · 2026-10-26T13:12:57-0500

Sludgemonkey44 said:
DEF was fresh from a truck stop pump on the way out, and i honestly didn’t look at the expiration on the box I bought I threw at it on the way home. It sucked down half a tank in 1200 miles. I normally get well over 5000 on a tank even with a substantial amount of towing included. I’m not thinking it was the DEF. It was almost certainly something malfunctioning in my DEF system.

Bad or contaminated DEF will 100% cause issues with your DEF system. Substandard or evaporated DEF leaves behind hard urea crystal deposits. These crystals can block the DEF injector nozzle, damage supply lines, and ruin sensor readings. Contaminated DEF (mixed with dirt, oil, coolant, or fuel from unwashed funnels or containers) can abrade and destroy the DEF pump, sensors, and Selective Catalytic Reduction (SCR) catalyst.

MT N8IV · 2026-10-26T13:52:45-0500

Get a code reader and look for the following:

P21DD (reductant pressure)
P24C / P24FE (particulate/NOx/quality issues)
P207F (Reductant Quality Performance)
P202D (Reductant Leakage / Reductant Pressure Over-Consumption)
P20A0 / P20A2 (Reductant Purge Control Valve Circuit)

If you have Forscan and can setup your dashboard, add the following PIDs:

Reductant Injector Duty Cycle / Command
Reductant Pump Duty Cycle
NOX11
NOX12

Use the NOX11 and NOX12 to see if DEF is being flooded. NOX12 results might read high versus NOX11 as raw ammonia from the DEF (since it is unused/combined) will be read same as NOX on 12.

AZsurveyor · 2026-10-26T13:56:32-0500

Vecman said:
Time to get rid of that entire system, especially since you hit the 100k mark. That would be the best choice for you. Don’t waste time trouble shooting, just get the tune and be done.

Totally on par with this and have never understood the notion of having to wait til "warranty runs out," when all the damage has been done and you are... well out of warranty. . .

Sludgemonkey44 · 2026-10-26T14:10:19-0500

MT N8IV said:
Get a code reader and look for the following:

P21DD (reductant pressure)
P24C / P24FE (particulate/NOx/quality issues)
P207F (Reductant Quality Performance)
P202D (Reductant Leakage / Reductant Pressure Over-Consumption)
P20A0 / P20A2 (Reductant Purge Control Valve Circuit)

If you have Forscan and can setup your dashboard, add the following PIDs:

Reductant Injector Duty Cycle / Command
Reductant Pump Duty Cycle
NOX11
NOX12

Use the NOX11 and NOX12 to see if DEF is being flooded. NOX12 results might read high versus NOX11 as raw ammonia from the DEF (since it is unused/combined) will be read same as NOX on 12.

Is that something I can read through my Banks Data Monster (or whatever that pod deal is called)? I remember being able to see and clear a code a few years back through it.

And speaking of codes, will some codes show up without a warning light coming on? Nothing has shown on the instrument panel indicating any codes being thrown.