# Anybody had a P20EE code on the Gen 2 yet?



## MRO1791 (Sep 2, 2016)

Not yet, but have only had a Gen 2 for about a month. Seems to be a common code with the Duramax Diesel:

http://www.duramaxforum.com/forum/showthread.php?t=917954

It would appear that it hasn't caused reduced power for others who were resetting it. 

Do you have a Scan Tool to reset? I'd still get it to a dealership ASAP, with the CEL on, they will do nothing if you reset and bring it in with the light off. 

Also, always look up your OBD 2 codes online. The OnStar description is so generic as to be useless.

Good luck and keep us updated on how it goes.

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## johnmo (Mar 2, 2017)

I have code readers, but it's been resetting itself. The CEL stays on more than it's off, but it's off and on a lot. I may just sit on it until my next oil change, which should hit later this month or start of next.


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## 91794 (Mar 25, 2015)

Check engine light can be a mere curiosity aside from being useful for preventative maintenance help... unless drivability or engine performance is affected . I am curious as to the code but there will always be software bugs causing trivial check engine lights for all the usual reasons. Any decision system always has a nonzero rate of false alarms (GOOD MORNING HAWAII!) . 


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## coalminer (Oct 31, 2018)

I just got this code on my 2017 with 23,000 miles. Going to drop it off at the dealership tomorrow and let them see what they can find, that is unless it turns back off later tonight.....


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## Ma v e n (Oct 8, 2018)

P20EE is for the NOx reduction system. It's typically an issue with out of spec DEF, or a skewed NOx sensor or failed SCR cat.(in that order....Though DEF and NOx sensors probably present equally. I don't know if it's a cause/effect relationship, that is if out of spec DEF poisons NOx sensors.)


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## coalminer (Oct 31, 2018)

And before I could drop it off at the dealership, the light went out, lets see how long it takes before it comes back on.


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## st1100man (Dec 17, 2017)

johnmo said:


> Here's the description from OnStar:
> 
> 
> 
> I contacted my dealer before Christmas and they couldn't get me in. I need to make a quick 700-mile trip this week. I don't mind emissions junk too much, but I don't want to get caught out of town with a worsening situation because I needed to head down the road.


I got a P20EE yesterday, as diagnosed by Oreilly's. I've got a GEN 2 2017 diesel. The car still ran great, with good performance and mileage. A DEF warning earlier in the day showed about 900 miles till I would be out of DEF. Will take it to local dealer tomorrow AM.


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## st1100man (Dec 17, 2017)

st1100man said:


> I got a P20EE yesterday, as diagnosed by Oreilly's. I've got a GEN 2 2017 diesel. The car still ran great, with good performance and mileage. A DEF warning earlier in the day showed about 900 miles till I would be out of DEF. Will take it to local dealer tomorrow AM.
> 
> The Dealer ordered a DEF injector and Module (DEF tank). The new Tank was defective because the heater inside threw a new code. So, thy ordered another tank module. I'm still waiting. The car has about 25,000 miles on it.


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## st1100man (Dec 17, 2017)

st1100man said:


> I got a P20EE yesterday, as diagnosed by Oreilly's. I've got a GEN 2 2017 diesel. The car still ran great, with good performance and mileage. A DEF warning earlier in the day showed about 900 miles till I would be out of DEF. Will take it to local dealer tomorrow AM.
> 
> 
> The final fix was: 1 new DEF injector (about $125 if purchased)
> ...


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