Found small leak where the top of the downpipe meets the exhaust manifold, riight behind the bottom of the heat shield.
(Used the blow air through the exhaust, spray soapy water and watch for bubbles method).
First put the Felpro gaskets on (replaces 20691-57E01) (noticing they were slightly larger in diameter-they was more "play" around the pipes), sure enough it didn't seal. Still bubbles .
Plus, if you rev it up and let go it makes a slight "put" "put" noise once or twice.
Same as before.
Ok, lets get the 4x more expensive Nissan part.
Get the ones from the dealer, in a Nissan bag with a nissan label and everything
Still, as loose as the Felpro, still "put" "put" as before.
The second time around I did notice there is maybe 1.5 mm (about 2/32 of an inch) or less gap between the mating surfaces right in the area where bubbles form. Which "shouldn't" matter if the two gaskets seal the pipes but that's where I'm at.
I figured I'll collect everyones' 0.02 before start taking everything apart again