What are you deleting? The best part about warranties is that you're covered regardless keeping in mind the issues that arise are brought to their attention prior to its termination. Keep a good log and you should be fine
I am wanting to delete the def/dpf by basically having a full exhaust kit on it and then tuning it. I have talked to a couple of guys at my dealership about my issue and just got blown off as my driving habits. But recently I have talked to someone and he just told me to take pics of it happening so I can have evidence; which I did I drive the same 30 miles one day every day and it seems like every other day my trip average changes from 33mpg to 21 mpg which is killing my overall average. I am stuck at 22mpg for tanks average. So I gave him the pics and sent it on to his manager who is supposed to take it up with GMC so hopefully find a fix. If they can find a fix that doesn't void my warranty plus extra $, yea I will take it and just delete it later, but if they don't or I continue to have this issue, I will delete since the mpgs was a big reason why I chose this truck in the first place.
I know a few buddies who've bypassed their dpf/def through all sorts of ways and increased MPG on their duallies but they're models were older, sorry to hear you're having issues have you tried a consistent startup/warmup procedure or do you just hop in and go every time? Cruise control is also a huge variable and most of my experience and research has taught me to avoid cruise control at all costs (hills, other cars putting that huge effect) just some food for thought
I keep the truck in the garage, right now it has been 70-90 day and night, my drive is pretty flat with my cruise set on 70 everytime. About 25miles out of the 30 miles is all highway and my mpg figures are from where I reset the average as soon as I set my cruise on the highway and check it as I am getting off my exit. When I got the 33 and 21 was both the same way, so its not like downhill then uphill back. One was on a Monday then a Tuesday. So I have eliminated all other variables and I shouldn't be seeing that kind of difference in mpg like that. I have talked to a few trusted diesel mechanics and they all came up with is that the truck is trying to go into a regen cycle. I was planning on getting like a 12 or 14ft trailer, since my little 5ft bed isn't going to get much work done, but if I can take that $1500 I was going to spend on a trailer for deletes/tuning so I can get better, consistent mileage, it would be worth it to me, plus never have to deal with filling up the def tank.
Every diesel truck owner i know run their trucks hard once a week. How they translated that to me was they opened it up on the road. This according to my friends cleans out sump tanks, and another collection point. I haven't done this on my diesel but for sure have done it on my gasoline engines. Im sure ill stick to the same routine but as for your variation of MPG I would put a code reader in it to start with, and maybe consider an oil change to dump out those shavings from your breakin. I am also working on upgrading my exhaust soon so if you decide to go that route let me know how it works out bud, sorry for the frustrations.
I have been basically giving it 100% throttle every chance I get and it is no change, still varying mileage, every other day. I am going to take it on a 800 mile round trip this weekend and see if that helps finish out that regen cycle that I think it is trying to do(even though I was told a prompt on the dic should pop up when that is happening.) But if not I will just hound my dealer some more until they do something. I have seen some nice partial aFe exhaust kits off amazon for pretty decent price to at least get rid of the muffler.
Have you, or anyone looked into an aftermarket replacement for the nose dam? I am not a fan of it, but I don't like exposing my hangy down parts. (both truck and personal). Either a skid plate or some other method of hiding/protecting the nuts and other hardware down below (I'm still talking about the truck)...
