[gr8britwjh]

.......could be imagining this, since it's almost imperceptible, but I thought I experienced it a lot today. Only seems to happen in 5th gear at around 3000 RPM as you hold it steady on the throttle (or at least that was were I noticed it most).

Seems almost like a hesitation (not really a misfire or loss of power; it's weird) but the pick-up is immediate if you step on the gas. By the way, the MCS only has about 350 miles on it. I did fill her up with Exxon-Mobil premium gas......maybe I got a bad tankful or maybe the ECU is simply adjusting itself ? Apart from this, it starts OK everytime and otherwise seems to run pretty smoothly. Any ideas ?

 

[kapps]

Seems like the yo-yo issue...but only in 5th . What software do you have? If it was the yo-yo, it would be there in the lower gears as well...

 

[gr8britwjh]

Kapps,
It's a brand new car so I assume it's got version 39.1 software. Funny thing is, I didn't notice the effect in any other gear. I'll have to go out today and conduct another on-the-road experiment