# Just got P20E2 and P20E4



## diesel (Jun 8, 2013)

I think EGT 2 is the most common failure sensor on our cars. In fact, it is the only sensor that I needed to have replaced (at 61K miles). I do recall there was some special testing the dealership had to go through to determine which sensor it was actually, but I don't remember the specifics. By the way i drove over 1000 miles with the CEL to no ill effect.


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## PanJet (Jun 18, 2013)

diesel said:


> I think EGT 2 is the most common failure sensor on our cars. In fact, it is the only sensor that I needed to have replaced (at 61K miles). I do recall there was some special testing the dealership had to go through to determine which sensor it was actually, but I don't remember the specifics. By the way i drove over 1000 miles with the CEL to no ill effect.


Yeah, I'm not in a rush to get it fixed. My 2-year license renewal is up in a couple months, so I'll need to get everything cleared up to pass Oregon DEQ, but I'm not terribly worried about it. 

The CEL actually went out yesterday, but came back on this morning with the same codes.

Oddly enough, I'm still getting readings on the ScanGauge from all three EGTs, and they all appear to be working as normal. I'm wondering what triggers the CEL.


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## mr overkill (Dec 1, 2013)

The voltage is erratic and the computer picks it up. Usually when the sensor is still cold


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## ChevyGuy (Dec 13, 2014)

PanJet said:


> I'm wondering what triggers the CEL.


Someone with a '14 manual could tell you. It might simply be slow to "wake up", or some other transitory condition. The light will clear if the problem doesn't return in some period of time. So the light being on doesn't always mean the problem is present right now - just when it turned on.


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## PanJet (Jun 18, 2013)

So I finally got my car in to be fixed this week. The verdict is that, as expected, EGT#2 was bad. However, this tripped codes on both #2 and #3 because of the differential readings between two, which also explains why the CEL would trip even though I was still getting readings on my Scan Gauge. It's not that the probe had completely failed, it's that it was giving erroneous readings.

On a side note, I also happened to notice the valve cover oil leak some others have experienced directly behind the turbo. I pointed it out, and they replaced a failed "cam plug." The leak was getting bad enough that the area was not merely a little dirty, but almost wet with oil on inspection. I'll keep an eye on it to see if it is indeed fixed.


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## diesel (Jun 8, 2013)

PanJet said:


> So I finally got my car in to be fixed this week. The verdict is that, as expected, EGT#2 was bad. However, this tripped codes on both #2 and #3 because of the differential readings between two, which also explains why the CEL would trip even though I was still getting readings on my Scan Gauge. It's not that the probe had completely failed, it's that it was giving erroneous readings.
> 
> On a side note, I also happened to notice the valve cover oil leak some others have experienced directly behind the turbo. I pointed it out, and they replaced a failed "cam plug." The leak was getting bad enough that the area was not merely a little dirty, but almost wet with oil on inspection. I'll keep an eye on it to see if it is indeed fixed.


Thanks for the update, and that totally makes sense about the EGT2. I never completely understood what was going on there until you posted that. EGT2 was the only sensor that has ever gone awry on my car in 153K miles so far.


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## KpaxFAQ (Sep 1, 2013)

Thanks for coming back with the completed update!


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## jkhawaii (Feb 12, 2016)

Did your dealer have the sensor in stock?


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## magnusson (Jun 15, 2014)

jkhawaii said:


> Did your dealer have the sensor in stock?


Mine took 2 days to arrive.


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## PanJet (Jun 18, 2013)

jkhawaii said:


> Did your dealer have the sensor in stock?


So far (knock on wood), my dealer has been excellent with getting parts. I've had the O2 sensor replaced, EGT2, and the valve cover cam plug (was leaking oil). On all three events, my dealer had the part either in stock or overnighted and installed next day.


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## Merchlewitz (Aug 3, 2016)

Hello All, I am curious what the correct readings are for the EGT's? I had a CEL come on and the report came back the 3 is reading about 188 Degrees F while 1, and 2 are reading 200 - 350 Degrees F. I am going to Replace EGT 3. I am just curious what the normal temperature readings are?


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## Rivergoer (Mar 30, 2017)

Those temps seem very low. My EGTs seem to run in the 500-650 F range for all 3 sensors. 

During regen they shoot up to 1,200 F or so.


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## TheRealHip (Sep 1, 2014)

So seems like everyone agrees that it is sensor #2 GM 55581035. There is a YouTube video showing you how to replace it https://www.youtube.com/watch?v=qq_0lNsYx9c


With the part in hand and a 17mm open end wrench, it is a 5 minute job.

Fixed the problem thanks all.


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## sparkola (Jun 9, 2014)

Mine was #3


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