Code P1777 after having a code of p0420 and changing the spark plugs

Converters bad...........or have a competent TECH monitor the sensors for proper function. Watching them is another way (long form) of diagnosing a failing converter , if you know what to expect.

Owner: Code P1777 refers to a transmission control circuit issue, did you have anything unplugged when you replaced the spark plugs ?

Hi, my car side motor mount rubber is out and everytime i push the accelerate peddale the car shakes and goes. after after stop sign i accelerate the gas peddale to the floor then tje car picks up about 5 second so do you know what is the problem