Recently on my 07 G35 sedan I've noticed that there's a weird lag in power for a split second while accelerating but it's very inconsistent. There's also a blip in power at around 3-3.5k miles that is also for a split second. I'm not sure if it's anything to do with my spark plugs (which I'm checking this weekend).I'm currently at 97k miles and I've had the oil changed regularly and kept all with all the maintenance.

Start with the plugs, If you have 97k on the original plugs that probably the issue.

I notice the same with mine when gently accelerating, typically when easing forward in a turn lane, especially on a slight incline. Ordering new plugs today, going to have a big weekend of maintenance next week.

I had that issue on original plugs but mine had 140k on them haha.... Gap was like .80 because they were so eroded. Those stock iridium plugs last a long time but also cost a small fortune. I used cheap NGK-R coppers on the turbo car since I have to re gap them and always change them out every season. They worked just fine, just don't expect coppers to last forever if you use them.