DEF Quality - Walmart Brand

[Little_Monster]

I took my 2011 Duramax to the Chevy dealer recently with the DEF fluid quality poor error message and the check engine light on. When I picked it up the dealer asked me where I bought my DEF. I told him it was the Peak brand from Wal-Mart. He said that I needed to buy it from somebody else cause the sample they tested did not pass. Just wondered if others had this same problem. They replaced the DEF, cleared the codes and did a regen. So far so good.

[Kennedy]

Couldn't say for sure, but not surprised knowing where it came from.

Blue DEF (Peak) seems to be a popular brand, but that could be just ad hype I guess. I've been running Terra Caire simply due to availability at local Car Quest. I want for the dash nag to drop to solidly below 1,000 miles and stay there and then add 5 gallons to the tank via 2ea 2.5 gallon jugs.