I was driving today and I went to past a truck on the road. As I step on the petal and pass the truck. my truck make wear sound and starter to blow a lot of black smoke. at that time the the truck went into limp mode. I stop and I have a scanner on the truck, as I run the scanner the code P0299 came on. If clear the code the truck run a little better until you step on the gas and the black smoke comes again and the truck goes again on limp mode. I have a LMM Duramax 4" pipe EGR delete, Injection pump 50 + HP, Electric fuel pump aftermarket air filter , EFI Live tunes and so on . the truck has been running fine for the pass 4 years, until today. Need help with this code. Thank you.