[Barry Allen]

It may give quicker results to clear it and see if it comes back?

The code reader from the parts store didn't have an option to clear it. It didn't even have an option to read the codes on the device.

The guy at the parts store just handed it to me and said "You know how to use it?" I thought maybe part of that was being 0ºF outside, and the other part was that white privilege kicking in that he trusted me. Walking to the car I noticed the back of the reader said "NOT FOR RETAIL SALE." I plugged it in and it blinked a bit and said "done" but there was no way to read the code from the display. I thought I did it wrong so I plugged it in again just to get the same result. I went back inside and told the guy and he said it had to be plugged into their computer to read the code.

I stood there thinking that's weird. Then, about 5 seconds later I said: "OH. That keeps people from stealing it..." and the guy said "Yes."

 

[Barry Allen]

For the drive back home today I noticed that fuel economy was back up into the high 40s (typical winter range) for the entire drive. The car had the CEL on but wasn't trying to do any regen other than when it was started cold today and was warming everything up.

This makes me wonder if the car is still able to do a regen cycle to completion as detected by pressure sensors? Who knows if the temperature sensor is back to working correctly, because I didn't clear the code to see if it gets triggered again. But it does make me wonder if the ECU can still regen fine even if the one or two temperature sensors aren't working correctly.

 

[Ma v e n]

Those code descriptions arent 100% accurate to the Cruze.
Both of them related to catalyst temp. 244C is "catatlyst temp too low during Regen", 144E is "Regen controls at limits, stage 2 too cold"
It sounds like it thinks your catalyst is too cold (EGT2)
Loose or clogged charged pipes/intercooler could cause this in addition to the fuel suggestion. And either EGT1 or EGT2

 

[Barry Allen]

Those code descriptions arent 100% accurate to the Cruze.
Both of them related to catalyst temp. 244C is "catatlyst temp too low during Regen", 144E is "Regen controls at limits, stage 2 too cold"
It sounds like it thinks your catalyst is too cold (EGT2)
Loose or clogged charged pipes/intercooler could cause this in addition to the fuel suggestion. And either EGT1 or EGT2

I reset the codes and went for about a 30 minute highway drive. At 55 mph I was achieving 25-30 mpg, indicating the car immediately went into a regen cycle after the reset.

The CEL came back, so I'm assuming it's the same codes.

So, suggestions? Should I order the #1 EGT sensor and replace it, because I can probably do that myself? It's a $32 part (and some shipping) so it could be a cheap attempt to repair it.

 

[Barry Allen]

clogged charged pipes/intercooler could cause this

Makes me wonder if it's intercooler icing. It has been really cold. Maybe I can wait until the thaw this weekend to see if it goes away.

 

[Ma v e n]

I wouldn't just shotgun one of the sensors. You've only got a 50/50 chance of getting it right, and that's assuming a bad sensor is causing it. (I do replace a lot of EGTs across all the GM diesels though) wasting money is wasting money.
It sounds like a cheap scan tool that can read data would be a better long term investment since you like to check on these things yourself.

 

[Barry Allen]

Now it's got me wondering if the issue I had the weeks prior (blowing blue smoke out the exhaust) is part of the problem. That was an issue that occurred with a certain set of conditions, and it went away. Did it leave lingering issues?

 

[TDCruze]

Now it's got me wondering if the issue I had the weeks prior (blowing blue smoke out the exhaust) is part of the problem. That was an issue that occurred with a certain set of conditions, and it went away. Did it leave lingering issues?

Would the EGT sensor reading incorrectly cause the engine to run rich and cause your blue smoke issue?
Now it has completely failed and giving the CEL?

 

[Barry Allen]

Would the EGT sensor reading incorrectly cause the engine to run rich and cause your blue smoke issue?

The blue smoke was caused by the car running rich for a regen or emissions heating cycle, and the very cold weather was likely making the extra fuel condense in the exhaust system. It was "wet stacking" for lack of a better term. Then, when I would pull away from a stop and give it some vigorous accelerator input, the fuel condensed in the exhaust would billow out the exhaust pipe in a cloud of blue smoke.

That's the nearest I can figure out what was happening, because the technician at the dealership wrote in the work invoice that there would be emissions error messages present that were not there.

 

[TDCruze]

I would be a bit surprised if these two strange issues were not related.

 

[Snipesy]

Would the EGT sensor reading incorrectly cause the engine to run rich and cause your blue smoke issue?

The EGT doesn’t really affect the engine. It’s really just to monitor Regen temps and catalyst operation.

It could mean longer regens... Where spilling out blue smoke is not uncommon. Especially in cold. I mean a Regen is basically running infinitely rich.

 

[Barry Allen]

What do you think the odds are that I continue driving and get the dreaded DPF FULL warning sign?

 

[TDCruze]

What do you think the odds are that I continue driving and get the dreaded DPF FULL warning sign?

View attachment 290753

Probably very good odds if you are not completing the regen each time you drive it.

 

[Barry Allen]

Probably very good odds if you are not completing the regen each time you drive it.

I just don't have the time and energy to deal with this for a while. I will have to wait and see what happens.

 

[TDCruze]

I just don't have the time and energy to deal with this for a while. I will have to wait and see what happens.

Be super handy to have a gauge/reader that you cold monitor soot % and EGTs. Then you could see exactly what is going on.

I still need to get something that lets me see soot % myself. I like having all sensor info at my fingertips!

 

[Barry Allen]

The emissions component warranty is longer and/or combined with the 60k powertrain warranty, right? If I end up needing a new DPF because of this I wonder if that's going to be a covered issue. Just spitballing for the worst case scenario.

 

[phil1734]

DPF is covered under powertrain, sensors are hit or miss, but most are covered.

This isn't great news I'm about to share, but keep in mind that you will be on the hook for a ~$150 diagnostic fee for the dealer to plug in a scan tool if it turns out to be a non-warranty sensor, and they won't tell you if it's warranty or not until they have done so.

 

[Barry Allen]

DPF is covered under powertrain, sensors are hit or miss, but most are covered.

EDITED

The emissions warranty doesn't apply because it's only for 2 years or 24,000 miles (8 years; 80,000 miles on covered major parts), and the sensors are not a covered major part.

However, the powertrain warranty (60,000 miles) covers the following: "Parts of the Emissions Reduction System such as the emissions reduction fluid tank, injectors, sensors including NOx and exhaust, and the Exhaust Particulate Filter."

So, it looks like the relevant sensors are covered by the powertrain warranty.

 

[Barry Allen]

I would be a bit surprised if these two strange issues were not related.

I'm going to make the polite ask to the manager if they can refund my prior visit, or bill it as warranty work.

Early Feb: "Hey, this car is doing funny stuff with the exhaust (blue smoke) that it's not supposed to be doing."
(they find nothing wrong)
A week later: "Now the CEL is on for exhaust stuff that's going wrong..."

 

[TDCruze]

I'm going to make the polite ask to the manager if they can refund my prior visit, or bill it as warranty work.

Early Feb: "Hey, this car is doing funny stuff with the exhaust (blue smoke) that it's not supposed to be doing."
(they find nothing wrong)
A week later: "Now the CEL is on for exhaust stuff that's going wrong..."

Likely be a long shot, but worth a try.

Seems most places can't or won't do any real diagnostics without a CEL on. Most seem to believe no light no problem, but many things seem to go wrong, and don't always give a CEL!