High idle
 

Lately my 370z when I fire her up has been idling high...about 2k. If I hit the accelerator and rev or or after a few moments of driving it goes back down to a normal level. Is this normal ? I do not recall it doing this when I got it which was last December time.

That is cold start high idle which should be normal. How cold has it been getting in your area?

2k rpm is a little too high should be no higher than 1700rpm, ur oil might be wrong weight or ur oil pick up might be lose letting air in, or in worst situation ur oil pump gear is cracked, or if ur up rev'ed, then adjust idle on start up of course if above isnt true.GL OP

High idle
 

High idle can be several issues. Cold, you should steady up at 1.5k, then drop down to 600-700 once the coolant is warmed up.

Vacuum leak, dirty MAF, bad idle solenoid...

LMK if you solve it; I'm still wrestling with a slightly high idle (900) on my Murano.