2016 odyssey aprox . 54000 miles. while under a lite at about 1800 or 2000 rpms on the tach will fluctuate up and down until you increase rpms. Will not happen all the time. Changed trany. fluid at 32000 miles .
It sounds more like an idle speed problem to me but your Odyssey has a 5 yr./60k power train warranty. I’d take it to a dealer while there was some warranty left.
I’m having a hard time deciphering those words.
Do you mean something like… while waiting at a traffic light?
If that is the case, the first thing that you need to know is that your idle speed when fully warmed-up should be far, far lower than that. Even with a cold engine, that is a somewhat high idle speed.
Then, there is…
All of this would seem to point to a problem with the engine’s IAC (Idle Air Control), which should be covered under the terms of your Powertrain Warranty. If your idle speed varies when you are sitting at a traffic light, you can rule-out the transmission.