I unscrewed the lock nut and added a couple wraps of Teflon tape. Although the lock nut is down against the housing and not sitting above, which I'm guessing isn't tightened all the way. I hope didn't move the bolt too much as I did it while still on the rail.
Oh yeah, One thing I noticed was that when I removed the turn down on the box I not only lost a bit of the low end but I had to be a bit more careful with the throttle as thick soles had it harder to feel the pedal and I sometimes lift off the throttle too quickly when starting on a hill and lug it. I also noticed the torque seems to have petered off around 3000 rpm. Or so it felt but then it would pick back up once around 3300. It didn't feel consistent though. Maybe I had a vacuum leak at the FPR?
With the turn down back in, the engine isn't as touchy but the low-end torque is a lot more forgiving. I'll have to see how it is on the highways though as usual, I'll probably lose some HP on the high end.
Oh, one other change which might account for the inconsistent feel. I put the roof rack back on and it's noticeable when I drive. I don't drive over 65MPH as it feels like I've got the sails up. I'll either take it off or leave and and start some new tests as the baseline is a bit different now.