I have heard alot of people saying the reflash is the way to go to cure a lot of the common problems. My biggest fear is a loss of power. Has anybody noticed a loss of power when pulling a heavy trailer. Also what do I do just take it to the chevy dealer and say give it all of the latest updates.

Had my LLY reflashed last Friday, took the 5ver out the next day to see how it performed. I felt like the LLY was smoother through the entire gear range when towing, power seemed more fluid for lack of a better term. I'm very happy with the reflash. I've only seen one other post where someone expressed a loss of power, not sure why though.

The majority of guys that have reflashed are posting positive results. Good luck. JJ :)

Reflash if needed only as last result. You can't go backwards and install the old flash.

Another thing that would be nice to know is when were most people's trucks made that got reflashed and it helped? And when were the trucks made that the reflash hurt. I know there are some people saying both things... My truck was made in April and I don't know if it needs flashed or not. I don't have all these problems some guys are getting them flashed for... It runs great and has no problems except crappy mileage, but I can blame that on my driving.

the reflash came out in early September to address specific issues people were seeing. If you purchased yours before that then you do not have the latest code, but you may not need it either. If you have no problems with your truck then really no need to take it in.. in my opinion. If you start seeing the particular issues then by all means take it in and also if you ever do take it to the dealer they should reflash it without you even having to ask. "theoretically of course" ;-)

True there are positive and negatives for some after the reflash, but we are talking about a very very small percentage of total owners on here. Plus every truck is different, acts different and is driven differently. lots of factors involved.

If you have the issues, take it in. If not.. enjoy your Duramax!

Happy Holidays
B.

The only reason I had it done was to cure the insane knocking while running a juice box, and it did. Truck ran fine without the box, now truck runs fine with or without the box.

04.5 lly, D/A, stock. built 6/04. Had the reflash because of the fuel knock and slight low speed surge. After reading some of the posts on this site, I understand the surge problem.
Low gear, lots of power, hi throttle responce, rebounding from my foot and the throttle, and the truck just wants to take off and go. With the reflash I have lost that throttle response, less sensitive, especially from a rolling start. Worst of all, the fuel knock won't go away.

I had the reflash to solve the idle surging. It would feel like the truck was missing at idle at a light. You could feel the truck shudder and watch the tach flutter. This problem has been solved and if anything I think I picked up some power. I suspect that they may have also given us some of the new programming in the 2005 trucks. I just towed 16,000 pounds through the mountains and from Chicago to Miami - no problems whatsoever!
2004 D/A stock, build date Feb, 2004

Steve

Ditto what Steve L. said. My truck runs better, initial mpg's are very favorable, and towing the 5ver the LLY just seems to have more balls throughout the entire range.

It is puzzling why some guys are not having positive results with the reflash? :( I'm one never to trust the dealers to install the correct programming. Given there are 2 different engines in the 04's is it possible to reflash the LLY with any LB7 reflashes? If so that can't be good! JJ :)

Had the reflash done today. Truck is quieter and more responsive. Mileage is about the same(21 hiway---17 city). I'm still a happy camper!:)

I also had my truck reflashed. I had the issue with parking lot suge. All though I dont no if the surge problem is fixed, the truck is quieter and mileage is about the same.