I feel the transmission is 100% normal.
I am thinking to do a trans flushing, what do you think?
The P0140 Oxygen sensor problem, a friend told me, might be the result of a recent misfire repair. This car had a misfire problem. I changed the coil, wire and plugs. Then the P0140 code appeared.
My friend told me I should drive the car for 500 miles and see if the P0140 cure itself.