I tried searching but it seems like noone has the same problem as mine.

So I've been lurking here for quite a while and just bought my second 98 GS400 last week. The car only have 95k miles and I have a problem when I feather the gas up to 1.8k rpm, then it shifts to 2nd gears AND it kinda holds the car back a little then shift, it feels like a soft slow jerk. But if I dont feather it at 1st gear and rev it up to 2.5k rpm and it shifts to 2nd then I dont feel that "jerk" anymore. Weird thing is that when I put it on Manual mode, it didnt have this problem and shift from 1st to 2nd pretty smooth. I know this is weird because it didnt happen on my first GS400 (sold it 3yrs ago cuz of some personal stuff). My first gs400 has 150k miles when i bought it and it shifts better/smoother than this one. I just did my 90k miles service and transmission fluid was flushed and it's new. So anyone know what's up with this? Much appreciate

 

First thing I would do... Try resetting the ECU by pulling the negative on the battery for like 5 minutes.

Obviously you are not the first owner of your current GS4. The car's computer studies your driving habits and adjusts itself accordingly for efficiency. It's probably not use to the way you drive as it's still running in the same manner that the other driver sold it in; resetting the ECU will give you a fresh start. Give it a little while and update us on the issue.

 

Ok so I did what you said and it's been a couple of days but nothing seems to be different. I noticed that when I put the car in Manual mode and left it at 5th gears, it shifts from 1st to 5th automatically very smooth. In automatic mode, it still doing that soft jerk....kinda weird

So is it bad if I put the car in Manual mode everytime instead of D and drive it "automatically" without using the button on steering wheel?