Background: I have a 2008 G37S Coupe 6mt.

The car seemed fine until the CEL came on when I turned on the car after work. I was driving it for about 10 minutes when it suddenly wouldn't let me go past 2,500 rpm. I parked it somewhere for about an hour (I was gyming it) then on the way home, it started to lurch and the revs would dip a little and then spike up to 2,000 rpm.

The next morning, I found out that Infiniti would charge me $140 to run a diagnostics, so I just resetted the ECU with the pedal trick, and the light went away. I've been driving fine, but if there was something genuinely wrong with the engine, would the CEL come back on soon? I don't want to have thrown away the code if there was something wrong with it, but the CEL came on very randomly and there didn't seem like anything was wrong. I felt like the revs dipping and spiking was due to the factory "limp mode."

Any suggestions/tips?

 

You def hit limp mode. The magic question is why did you hit limp mode.? Were you driving normal or spirited? If it hit limp mode under normal driving, you have a problem.
Only time I ever saw the g hit limp mode was during dyno session on 90+ degrees day with 15 min cool down between pulls.
Once the oil temp spikes over 210-220 the motor does this to keep from failing.
Seeing is believing, I then had the shop install the oil cooler.
After they installed oil cooler, easy 40 degree drop in temps, car never hit above 180 after the install same day. This was the reason I bought an oil cooler. Again this is just from my own experience. Good luck with getting all fixed.

 

Thanks, I'm starting to think the CEL wasn't a fluke, but I needed to get it out of limp mode anyways because I had to get to work!

I think it has to do with cleaning the throttle bodies and/or filters. I'll do that this weekend. It'll probably fix it.