Thank you for taking time to read. I googled this question and brought me here but didn't fully explain. My automatic 2005 G35 coupe is having sluggish performance, slow acceleration and high idle. on the thread that I originally read it said something about loose plenum spacer bolts and I was hoping someone could elaborate? please and thank you

 

Plenum spacer is an aftermarket modification to the intake manifold. Have a professional mechanic look into his if you don't hear any weird sounds in the engine bay.

 

JNav, "Welcome to G35 Driver!" You didn't mention any error codes but your G is sluggish, have a Nissan mechanic check it out. Could be a small adjustment since your idle is high, Nissan can correct this in seconds. They'll also be able to pinpoint any issues that might cause the sluggish performance you're feeling...Gary