Gentlmen,

Need some help figuring out some issues. In the last year I've had a NOX sensor fault (dealer repaired) and a DEF heater fault (I replaced). I'm now getting an EGT sensor fail. Every fault is with the same system.

I'm also realizing that while I'm getting the exhaust system cleaning message, my DEF level is not being depleted.

All the dealership wants to do is change out fault codes but I think the true issue is elsewhere.

Any ideas???

Thanks, Jaysen
2011 F250 SD FX4 6.7L (stock)

 

Def is used in your scr not your dpf...def has nothing to do with regens. Faulty components have been seen in the 11s

 

Thank the EPA for the emissions on the diesels.

Mine's a 13 and I've had both the NOx and EGT sensor issues. Dealer fixed the NOx and I replaced the EGT. I did that just because I didn't want to wait three days for the dealer to do it. It was only $35. Knock on wood I don't get a DEF fault.

As Suzuki said, DEF has nothing to do with regen. It's purpose is to cut down on the NOx emissions and break it down into less harmful substances. More heat = more NOx = More DEF used. That's why you use more towing.

 

So based on on the discussion of DEF, should I be worried about DEF not actually being depleted?

It sounds like you all saying it cuts down on particulates but won't have any mechanical impact.

Another question, how difficult was it to change out the EGT sensor? I've heard horror stories that you need a torch and they are prone to stripping.

Thanks for the help guys.

Jaysen

 

I wouldn't worry about it too much. Mine takes a while to go down. Especially if I'm not towing. The trucks doses it per feedback from the NOx sensor and others. I honestly don't pay much attention on how much I use. I check every once in a while and add the 2.5g when it hits less than half full.
It's not particulates DEF cuts down. It's the NOx gases. The particulates are caught in the DPF and get cleaned out during regen.

The EGT wasn't to difficult but you do have to be careful so you don't twist off the bung. I spray it a few times with some PB blaster and let it soak. I then cut the wires (no going back at this point) about 1/4" from the sensor and use a 6 point socket. I carefully apply pressure until it breaks free. I have heard the horror stories and some do use a torch. Mine wasn't too bad so I didn't have to go the heat route.