If your clutch pedal makes noises when you push it in, it's more than likely worn bushings. You can attempt to lubricate yours, but that usually ends up making a mess and it's incredibly difficult to get any lubricant in the actual bushing. Replace the bushings, putting some thick grease all over them.
Sold individually, the clutch pedal has two of these.
This bushing is installed in the clutch pedal itself, right where the rod fork of the master cylinder connects. This eliminates free-play in between clevis pin and the pedal arm. This bushing often crumbles and falls apart over time, especially with upgraded clutches (with heavier pressure plates), which will cause the pedal to squeak and create a popping sensation during actuation. Installs in about 5 minutes with simple hand tools.
Please be aware that Nissan / Nismo / Infiniti pricing is subject to change.