I am just coming across this post and am having very similar issues with my 2018. I just picked mine up at the dealer and they indicated that they could not duplicate the issue but the pedal vibration is still there. I may not have explained the issue correctly to the service guy but your post will help me hone in on it. Just curious but did you ever have a dealer take a look at it or was yours post warranty? thanks.
I feel your pain!!!! I had a 2017 that had an extremely annoying gas pedal vibration that I was never able to cure, so I traded it in and got a 2019 ..... problem solved. I tried countless things to fix the issue on my 2017 to no avail including replacing the exhaust system, tightening ever bolt on the underside of my truck countless times, getting a tune that altered gear shifts thinking it was a transmission issue, putting weights on the bottom of the gas pedal to see if it was a harmonic frequency issue, putting weather stripping between components that could touch and potentially rub, etc, etc, etc..... I hate saying it, but I was completely defeated by my 2017 and replacing it with my 2019 was the best thing that I ever did. I now have a truck that I love driving!!!!
