I have a 2011 hino 268 that is having fault code p0402. It’s losing power only going 30 mph and the turbo seems not boosting and i can hear hissing sound from the exhaust and air bogging out from the air filter whenever it losses power. During mornings and night time it runs good plenty of powerr.whenever the weathers warm and im going uphill it losses power.i let the truck sit to cool down for an hour then it’s okay again until the engine gets warm again. So far we replaced the turbo with brand new oem, all the intercooler hoses, maf sensor, fuel filter, fuel water separator, air filter and cleaned/ baked the DPF filter. Still to no avail but that did make the p0299 code go away. I still have the p0402 active. We are out of idea my mechanic advised me to take it to the dealer for a diagnostic. Dealer advised me to change the egr valve, egr temp sensor and egr cooler. Have you seen egr valve go bad on this trucks? It’s pretty pricey. I don’t want to keep throwing parts on the truck and still having the issue afterwards. Please help