1999 Lexus GS400

I recently cleaned the MAF and throttle body on the GS because the acceleration on the car was delayed and jumpy. The throttle body was really dirty and extremely black -- had it all cleaned up with throttle body cleaner. The air filter was also changed because it was extremely clogged and black as well. Well after i put everything back together, the car was running nice again and being very responsive.

However, I immediately noticed that when the car comes to a complete stop, I can feel the transmission downshift to first. This only happens when I slow down enough for the car to go back into first (2nd-1st). Upshifts are smooth and fine.

Any ideas what can be the problem? Just a coincidence that the tranny is going out?

Im resetting the ECU right now to see if it just needs to relearn (not sure how the tranny would be related though, but worth a try)

 

Fixed the issue. ECU reset was all it needed.

 

2001 Lexus IS300. While in reverse my car feels like it's jerking when I do not have any or little pressure on the accelerator. Is this normal? I just bought the car three days ago and I am new to the Lexus world. If anyone can help I would greatly appreciate it.