[2018 3.0L powerstroke]

So I bought a 3.0L at the start of this new year and I’ve noticed that the DEF has not gone down at all since I’ve bought it and it is now March. Is my truck deleted already??! I have no clue It was something I just noticed on the def part. Not too much black smoke will come out but a decent bit where you can see it will. I’m just tryna see if anyone can tell me yes or no, or if I can just plug a reader in and it’ll maybe tell me.

 

[beaker]

If you run your finger on the inside of the tailpipe, it should be clean. If it comes out black, there is something wrong with your DPF or it is missing. Also, if you see any black smoke at all from the exhaust under any condition, the emissions system is not intact.

 

[jmperlik]

While the 3.0 Coffee Table Book makes the DEF level gauge sound like a demented science project:

in practice it isn't very precise = it basically measures three (3) basic levels:

• 100% Full
• 50% Full
• Getting close to empty
  • Countdown starts at 500 miles
  • IPC uses the following to figure out when to drop you into limp mode:
    • odometer
    • prior consumption rates

I wouldn't worry about it for another 2500 miles = you are using DEF but the DEF level gauge doesn't work like the float system in your fuel tank.

 

[beaker]

@jmperlik is correct. The DEF system can run a ridiculous distance without needing a top-off if you are not towing. The DEF sensor is the same as the one in the superduty, if I am not mistaken. My distance-to-empty meter for DEF often reads almost 5,000 miles. I jumped to a conclusion about your emissions system overall since you mention being able to see a "decent bit" of black smoke, which is a big red flag to me. If you look at the tailpipe of an emission-intact semi, bus, or a smaller truck, the inside of the exhaust is typically almost shiny.

Congratulations on your recent purchase, by the way.