2011 Versa random sputter at warmed up idle?

[Flybye]

Hi all. So a 2011 Versa in drive has this strange sputter that happens only every few seconds. It's smooth then jerks for a fraction of a second then smooth again. Then jerks again after could be a few seconds to well over 30s. It is very random. Thoughts? Driving is always smooth. It happens in N, but you can't feel it as much as in D. It never happens when cold.

I'm thinking vacuum leak, but I think the sputter is too random for a vacuum leak, and if it was a vacuum leak, wouldn't it also happen when cold?

What I can say:

1) Versa has 85k (probably oem plugs which I read are good for 105k?).
2) Happens with AC compressor on or off.
3) 4sp auto and not cvt.
4) New air filter.
5) MAF has been cleaned out with MAF spray.
6) Throttle body has been removed and cleaned with TB spray and toothbrush on both sides of the butterfly.
7) New seal between intake manifold and throttle body.
8) I have done the Nissan idle learn procedure.

I almost tempted to remove the radiator lines to the throttle body. Anyone know if that could affect it? I am in a climate not concerned with freezing.

[offthewall]

Hmmm, is it misfiring? Are there any engine codes? I've experienced this on a Versa 2012 1.6L CVT. It was around 100k miles, the issue was the ignition coils were going out. Engine was misfiring though and showed code for misfiring, and we replaced all 4 ignition coils and seems to be running great now. The spark plugs were changed prior to the misfires. Even though it says 105k, 85k is getting close. If those spark plugs weren't replaced yet, depending on how you drive the vehicle and many other factors, the plugs will deteriorate at different rate, should check it and see if they're going bad.

[Flybye]

Zero codes. With the Tb disconnected, I was pretty tempted to check sparkplugs. But was meh about it since that meant having to take another trip to get a manifold gasket. Guess I’m just going to have to man up.

Did yours misfire in idle and driving?

[offthewall]

I don't remember if I could feel it misfire during idle, but I do remember feeling the jerk while driving and having to pull over cause I knew it was misfiring. You really feel the misfire during acceleration, and then sometimes it would be ok. The code eventually came up saying it was misfiring on which cylinder, so I swapped the ignition coils just to be sure, and the other cylinder misfired, and since knowing that if 1 was going out, eventually the other ones will follow, I just replaced all 4 ignition coils.

[Flybye]

I would have done the same. If 1 coil is on its way out, who knows what condition the others are in. Accelerating I get zero trouble. It is silky smooth. When I give it gas from a stop, it will have a very mild stumble, but never again. It doesn't even always do it when I give it gas from a stop. But zipping around and giving it gas while driving? Nothing. What really bugs me is the random sputter happens when cold almost as if no longer running rich is a factor.