Good Evening,

Intro: I have been a long time lurker for DIY and general maintenance issue. I have been doing extensive research on the following topic but haven't come up with a solution. It is in regards to a 2001 Honda Accord EX, 4 Cyl. Automatic Transmission. 324K miles.

Problem: I frequently find myself "slamming" and "slipping" gears when driving in and around town. It is not an issue when I am on the highway and set at 65MPH. Issues seems to pop up between 4000 and 6000 RPM.

Data: The following codes are present:
P1259 Vtech Fault
P1166 O2 Sensor
P1167 O2 Sensor

When dealer assessed the issue, "You need a new transmission."
When auto store assessed issue, "Start with the VTEC, likely problem. VTEC has something to do with the RPMs. Could be a selenoid on the transmission though...."

I have assembled a video in hopes one can get a clearer understanding of my problem. If it is the VTEC selenoid like the individual at the store believes, I will certainly do a complete work-up with pictures to aide any individual who may have this issue in the future and to help the forum.

Actions:
1. Changed the oil. Topped off to within the dots on the dipstick. Still slipping & slamming.


Notes: I have only used mobile 1 synthetic 5w-30 since I purchased the car with 65K miles. Oil changes every 4K miles. Presently within the dots on the dipstick. AT fluid changed 75K miles ago, still topped off.
Video Link to Youtube:

 

I'm going to go with the transmission is on its way out. Honestly you are lucky to have has many miles on it as you do if it is the original transmission.