My car keeps shutting off can't trust to drive it anywhere check engine light is on.

Question

Please help, while driving my car it shuts off unexpectedly; or while idling I need to know why; I have replaced the fuel pump and fuel filter, and ignition key and switch; now I get this code P0431 stating warm up catalyst efficiency below threshold bank 2 what and where is this located? - I took it my car to a GM dealer who changed the ignition key and switch but they could not find anything on their machine regarding the inadvertently shutting off, but on my CarMD I get the code I have entered above. Do you know what is wrong? It would be most helpful.

Answer 1

P0431 Bank 2 Pre catalytic insufficient

This code P0431 has nothing to do with the vehicle shutting of unexpectedly, What needs to be know is when it shuts down are you able to readily restart or does it shut down and take a while for it to restart. . If you are driving and coming to a stop or slowing down and it stalls , this would be the throttle body problem where the idle is controlled by the throttle body, you can do a throttle body cleaning which can help. and better yet perform a idle relearn. To do the idle relearn the engine has to be warmed up. vehicle in park, turn the ignition off for 30 seconds. Turn the ignition on , with the engine off. for 60 seconds.  , Turn the ignition off . This ensure correct idle operation. In the process of doing this you can hear the throttle doing the relearn.