Kia Sportage stalls and buds

2011 used Kia Sportage with 35000 miles. At slow speeds it stalls. In addition when the tank gets between 1/2 and 1/4, it jerks and bucks violently, all of the engine lights go on and it stalls. I tis under warranty. Kia thinks it is the PMC valve but won’t replace it because they cannot duplicate the codes to get authorization from Kia to do the repair. I bet if it was not under warranty and they were not footing the bill they would replace it and whatever else i asked them to do. I think it is the fuel pump for the jerking and bucking but I do not hunk they did anything about it. Suggestions?

It’s under warranty. It’s their responsibility to diagnose and fix it. Leave it with the dealer, get a loaner car from them, and tell them you won’t take the Sportage back until it’s fixed.