Looking for the right thread. 2003 civic ex auto.

while coasting at around 35mph, the trans seems to get confused and bucks between gears. Mashing the pedal it stops.
Car is new to me, so I will dump the atf and fill with Honda stuff. That is said to fix it sometimes. Next is cleaning the solenoid. getting no codes for the trans.
Any other advice?

 

Sounds like the EGR valve and/or EGR ports might be clogged with carbon - common issue on many Honda engines. Is it really the trans hunting gears or stuttering engine like going over a washboard road? A drain and fill of Honda DW-1 ATF would not hurt. Don't flush and use only Honda ATF.

 

EGR was smoky for sure. I cleaned that as well as the idle speed controller. Crossing my fingers on this build. Got my genuine atf. See what happens I guess.