So I recently purchase a 2009 is250 a/t RWD with 96k on the ODO about 2 months ago. It’s right under 98k now. Absolutely in love with it except for one thing. The transmission seemed to be completely fine when I first got the car. As I became more used to the car I noticed that first gear seems a little tougher than the others. It’s almost like it takes a few milliseconds more to catch second gear than all the others. Some days it seems smoother than others. I realize this transmission learns to your driving habits so I’m assuming it’s that because sometimes I drive slow and other times I drive incredibly fast and hard. I have also noticed a stutter when I come up to a stop sign. I feel as if that was not there when I bought the car but I don’t really remember. It’s like it can’t downshift fast enough when I go to hit the gas again, even if I do it lightly. Possibly torque converter issue? It’s really frustrating because it makes city driving a pain. I use snow mode in highway bumper to bumper traffic but for just driving around the city and hitting stop signs this slight transmission catch is irritating. I know this transmission is also sealed and you can’t do a full flush but I was thinking about doing a partial flush. I’ve talked to several reputable shops and they can do a 30% flush for $100. On top of those 2 issues 4th gear seems to rev up about 200-500 when it goes into fifth occasionally. Doesnt happen all the time but when I’m driving up a hill it will hold onto 4th gear way to Long and almost rubber band into 5th as I crest over the hill... not smooth at all... it’s just the car favors 4th gear the most out of all of them... is there some transmission update I can get at the dealer? I feel like this is all just bad software... I’ve done 2 ECU restarts by unplugging my battery. My MAF sensor is in eh condition.

current mods: cold air intake, 19” rims, r1 ceramic drilled rotors, ceramic pads, medallion exhaust.

Dang I never thought about that... previous owner had bought the intake but drove really slow so she probably never witnessed these issues. This makes total sense. My cars RPMs seems a little jittery when coasting at 1300-2000 as well after a good hard run which explains for a warmed up MAF. Would you say the transmission catch coming from a dead stop could be caused by a overly hot MAF?