Our card is pre obd2 it has a self check. Similar to an 88 ford. Only code it gives is 3 and 5 oxygen sensor and egr. Nothing to do with shifting. For the first mile car shifts great then goes into its mode. Heard it could b the solenoid switch and the missing kick down switch. There is a way to check the solenoid on the transmission right. I looked up parts for the kick down switch and the solenoid. The solenoid is a long kinda part color was a gold color. Not sure if this is the right thing, but found another kick down switch. Can the removal of that switch b the cause??? thanks for the help

Oh will check and see if there is a yellow triangle on the speedo with key on. Will check that tomorrow thks again