Pardon if I did not delve further to look this up but here is my issue.
2008 G35x, just hit 73K miles. Car has [I]always[I] run like a charm. I was at a light today and very suddenly (or so it seemed) the car felt jittery with rough idling. Acceleration seems normal but at highway speeds it would frequently hesitate and jolt. At a light, idle drops at times to 500-600. After about 15 miles like this the "service engine soon" light came on.

I am up to date with belts, hoses, fluids, but did respectfully decline the dealers $700 60k service. Just odd that this happened so abruptly.

As always, any and all ideas very much appreciated !!

Thanks...

 

Check what codes its throwing

 

There is a ecm reprogram available for the drop in rpms at idle and for hesitation. This may help a bit but definitely doesn't explain the ses light. Willing to bet it is a p0014 or a P0024 exhaust valve timing code from the symptoms that you are describing. Hope this helps bro.

 

Symptoms were worse this morning. Took it to a different Infiniti dealer (would not bring a Little Tikes car to my previous dealer)
The cause was a bad MAF (mass air flow) sensor to one bank. Why you ask?? I used what turned out to be completely substandard aftermarket air filters, one of them warped and the large gap let all of the contaminants get in.

Lesson learned....

 

I'm bumping an old thread, I know, but I was read off these 2 codes today at my local Auto Zone. After a little reading, am I understanding that I am going to replace (2) timing covers? I've also been having idle and hesitation issues for a year and I got around last month to cleaning up my throttle body which seemed to help a lot with the hesitation.

I gave this car to my wife a little over a year ago and I don't think she's been taking car of the maintenance on this thing. There's not an oil change sticker and I suspect she hasn't been getting the oil changed. It now shoots out white smoke on start up and after some research I learned that changing out the valve covers and PcV valve might fix this. If not, it might be a costly repair. Any thoughts?

 

I'm sorry, the codes I quoted in my post, p0014 and p0024.