Loss in acceleration + throttle response ??

Mike's 370z

I had the same problem, starting this spring. I found that if I reset the ECU by disconnecting the battery, everything resets and the car runs really well for approximately ninety days. I repeated the procedure when the sluggishness returned, and the problem was corrected.

Several other things noted:
I run Red Line 5w-30 exclusively, and make sure its always topped off, as I noticed similar symptoms when the oil is not full. I switched to Red Line after reading all the posts on high oil temps. Red Line synthetic will easily handle the higher temperature requirements and contains ester, as recommended by Nissan.

I also noticed that the ECU seems to have issues if I switch gasoline vendors, so I use Shell exclusively.

I replaced the air filters at 10K since we've had a horrific winter with much dust from the sand left over on account of the snow plowing efforts.

Aside from the periodic ECU reset, the car operates really well.