I would get it done.
I haven't lost mpg but have gained some (1-2mpg around town). As far as regens, so far in only a few hundred miles have seen one and it was easy to detect. If you miss the milimicrosecond dash notification, mpg WILL disappear for a while and your other indicator. Only possible negative I've seen is that the 5-6 shift happens a little later on the rpm range but the first 4 seem stronger. As far as others losing mpg - that may be due to other factors as well as the reflash, like cetane rating, ambient temperature, driving style, etc

. Oh and mine, a 2011 Job 1 and the worst of the current breed of 6.7 engines - transmission combos

 

I find it interesting that people have so many different results of the same flash.

 

You have a 2013, I say have them upload it. Many here have had good luck with it by not having any changes in behavior. I have lost another 1 MPG. I am in the mid 12's now and that used to be my towing mileage, which is now 10. It has certainly increased fuel consumption for a reason I can't explain. I'm not pleased with it on my 2011, not limited to the MPG.

 

Funny, it sure did the first time it went out.

 

Had a regen at 75 percent load insted of showing 100 on my cts

 

Nope!!! It was to reduce the temps and increase def consumption it would appear.

 

I've noticed the same on my 2013. My truck starts a regen at 2.58 soot load where it used to start at 2.78. Also it stops the regen process at around 1.5 where it used to end around 1.2-1.3. I've had about 4 regens since the update and this behavior has been consistant.

 

Had the recall flash done last week. Now I've noticed a shudder on the 6 to 5 downshift under light throttle while going up a hill. Never noticed that before.

 

Have you been back to the dealer for the shudder since they did the flash, PlayersZ28? Please let me know the current odometer reading on your truck as well; I'll use this information to research any available options.

Brittany

 

No I haven't just noticed on the weekend as that was my first time highway driving after the reflash.

About 78,200km on it now. Have FMPP & Ext Warranty until Jun 15

 

Thanks for the input fella's. Very much appreciated.

 

Flash was completed on my 2012. Trans still shifts as smooth from day one, regens around 300 mile intervals, and fuel mileage towing 5th wheel still around 11.8 without towing its also the same at 16 city and 18 freeway at 65. Now if there's anything different about my truck since the flash was I removed the Rancho Shocks and installed the 5100 Bilstein's, wow what a difference. Two of the Ranchos wouldn't extend after compressed. Truck has 21,000 miles.

 

Dak,
I think that those of us that have seen an increase in MPG since the flash are the early build 1 trucks that also received the 400/800 flash early on. I know when I got that reflash I lost about 2 mpg (nope, wasn't cause my foot was deeper into the floor board ) but with this latest reflash it has increased back to my original off the showroom floor MPG.

Good news is I still have not seen any posts where someone is left stranded after the flash!

 

just did a 1400 mile round trip. Averaged 19.3 mpg going north, left at midnight so no traffic. 18.1 back down driving faster and much more traffic. I was averaging around 16 before the flash. I was getting the higher mileage originally on the truck than took my truck in for a repair and it got reflashed and my mileage dropped about a year and half ago. Than just had this reflash done about 3 weeks ago. I'm glad i had this newest flash done. I have an early 11.

 

I just had the Recall 14EO3 done. The only thing that I have noticed different is the shifting points of the transmission seem to be a little sooner than before. And the "double 3rd" shift has moved to 4th. My truck is an April 2010 Job 1 build.