I have a 2012 veloster 6 speed. About a month ago I noticed that when I accelerate the car kind of lunges like it's not getting the power for the speed. Almost feels like if you were in say like 6th gear and trying to do 30mph. If I accelerate slowly it's fine, but if I step on it it lunges. Boyfriend says he'd bet his paycheck it's the high pressure fuel pump. Any thoughts? I have 150,000 miles on it.