Fletch379

I have the same issue with my 3.0L. Fuel knock is horrible, even more so when it's trying to regen. The manual supplement states this engine is designed for Top Tier Diesel which is sold at select retailers, none of which are anywhere close to me. GM only recommends their diesel fuel supplement which is a joke, none of the dealers around me have it in stock and is way over priced. I use Opti-Lube Boost which is Cetane and lubrication only. It helps but does NOT eliminate it. Very Frustrating but not nearly as frustrating as having multiple CEL issues and the dealer not being able to find the root cause. Trucks has been at the dealer for weeks now and will likely be there a few more. I have called GM and this has supposedly be escalated to their senior service team for whatever that's worth. No communications from them either. I do know the codes are emissions related. Supposedly there is a service bulletin but the troubleshooting is fairly extensive. Truck has 6500 miles on it. ANY ideas of how to get GM's attention to help solve my problem would be greatly appreciated... I'm new here so please keep the heckling to a minimum..LOL

What engine if you dont mind me asking?