3rd gear rpm jumps up? (AT)
 

So I drive a 2013 AT FRS and I'm not sure why this happens. It happens like once a day maybe or once a week or once a month or something I don't count lol. But I'll probably be pushing it when it happens.

High, but not redline rpm in 1st. Same in 2nd, but a little lower rpm. Then I'll take it into 3rd gear and slow down a bit before I hit something. As I'm letting the rpms slowly drop, all of a sudden I'll jerk forward (I guess because it cut fuel?) and the rpms will shoot back up like a thousand or a half or something. I don't pay attention to how much, but it does go back up. Then it'll slowly drop back down like normal again as if nothing happened. The car drives fine like normal and all, just that happens in 3rd gear. Kinda weird.

It does happen when I drive normally sometimes in 3rd like I described up there, and it'll be a lot less dramatic, but I don't know what causes this. Back when I first experienced it, I did a full oil change, tranny fluid change, and diff fluid change. I don't know if it's placebo effect, but I felt like it shifted a taaaaad quicker and the issue went away. But it still happens today after awhile. I don't know when it started again if it wasn't placebo.

Mods:
OFT stage 2+ OTS
UEL header
Resonated front pipe
(nothing else in the engine bay or exhaust)

Are you doing moderate to hard braking in sport mode when this happens?

In sport mode it will downshift when doing anything more then "normal" braking.

Oh no. I'm in manual mode with no braking.

I've driven in sport mode while driving fast and had to do hard braking before. The car will downshift at such high rpm. The sound scares me because I don't expect it haha.

Can you take a video recording of your speedometer doing what your describing, and a corresponding data log of the event occurring?

Have u looked into the clutch disc in the automatic transmission?

Sent from my SM-N960U1 using Tapatalk

Doesn't happen often enough for me to whip out my phone everytime. It's so random.

Nope. Didn't bother me enough to take apart the tranny. But if that's anything like in a manual tranny, I wonder if that's why my 1-3rd gear feels like it's like wanting to stall or like it's not catching the gear kinda thing when first accelerating sometimes.