I have a reasonably well kept 2008 3.5 manual. I've had it a year and it has around 92K miles.
I've had to do a few things to it and I'm a grad level do it yourselfer.
Seems the clutch started slipping a couple months ago, so I replaced the clutch with a stage 1 clutch,
which I'm told is stock disk, but pressure plate has a little bit stouter springs. This was quite a job,
so do not want to do it again for a long time.

Anyway, my question;
Seems that maybe the reason the original clutch went out might be related to the sloppy throttle response on this car.
It seems that when you take your foot off the gas often it takes the engine a full second or more for the RPM to decay back to idle. What this means is as I go through the gears I have to do it lazy or the car will jerk and jump and I'm putting extra wear on the clutch.
This is the type problem I would normally expect to be something interfering with the throttle cable, or a weak spring.
But, as you guys know, this car is 'drive by wire' so it's either in the software or some calibration thing.
I followed the calibration procedure for the gas pedal, but it did no good.
I've read where this car is considered to be a clunky shifter, but it's not the shifter or the clutch, it's this throttle problem.
If I drive it like my pickup truck it's fine. Wind it up, push in the clutch, take your foot off the throttle, throw it in the next gear and don't drop the clutch for a second or so and it's fine. But if I try to go through the gears like I'm driving the sports car that it actually is, it'll jump and the clutch will slip like I'm not blipping the throttle correctly, even though I am.

Is there a fix for this? Is it possible some sensor is not calibrated correctly like the air intake or throttle plate sensor?
Wouldn't that pop a code and give me a check engine light (which I don't have)

Oh - and yes - I do know how to drive a stick. I'm 59 years old and have only owned 1 automatic in my life (and regretted it)

Thanks in advance
Larry

A whole lot of cars do that now and intentional, it lowers emissions at decel. The issue can be aggravated by a very small vacuum leak. Might check the TPS output too, if one could lower it a tiny bit that might help. If it was a cable throttle you could simply drop the butterfly a tiny bit closer to closed too but won't work on throttle by wire.