Hi, I have a 2011 G37 Coupe 7AT 120,000 miles

The problem: I am experiencing soft idle bouncing when cruising, 3-5th gear. (If I stick it into manual mode, and drive at a constant in 3-4th gear and hold throttle steady position, it starts to give power randomly and not) Also when it shifts low after acceleration I think it drops down to fourth/fifth the car shafts shutting/shaking when I’m giving slightly more gas. But picks up normally if I give more gas. I’m often see’ing the RPM dip down low at stops often. No Check Engine lights or codes seen thru admin tuning app.

When it drives in lower gears when cruising the shutting is unbearable too me. Like you can feel it thru the dash and you seats.


Modifications: (these mods have been on for three years to note)
- long tube intakes
-1320 hi res cats
-bolt on exhaust
-admin tuned


Things I have attempted:
-cleaning the throttle body’s
-cleaning maf
-replacing o2 (was needed wire were broken)
-recently did motor mounts
-check IACV
-new battery and ground cable had to be replaced
-checked long intakes for broken couplers ect
- I did the idle relearns (idle sits around 750)


im planning on buy a smoke machine next, but thought I’d ask too see if anyone can shed some info before I do anything else. Thanks!