My 2005 GTI has been decelerating while I’m driving on a certain section of the freeway. It’s a steady incline for about 1/2 a mile, the altitude changes (my ears tend to pop). The car starts to decelerate, I take my foot off the pedal for a couple of seconds and then press the accelerator and it’s usually fine.
However, a couple of weeks ago it totally stalled out on the freeway, it restarted fine. I took it into the shop the next day, my mechanic is not 100% sure what the problem is, he replaced the crankshaft sensor. Turns out it’s not the source of the problem, I am still decelerating on the freeway. I had a tune-up and new battery installed a month ago, so I don’t know what the problem is. Any ideas?