Recently, my friend, who is a mechanic, installed my KS for me cuz he's really nice. I got the car back, did the self diagnosis of the ECU, and STILL got ghost code 0304!! I was pissed. So i popped the hood, made sure everything was working/connected and then did a self-diagnosis again. ECU code 0505 came up! Yippee! Nothing wrong.

What I don't understand is this: Shouldn't fixing the KS prob automatically clear the KS error? As soon as I fixed my O2 sensor, the CEL just went away. No resetting of the ECU involved. Should I expect the KS ghost code to come back again?

 

Mine didn't go away right after the install either, I reset it and it was gone FOREVER.

 

The CEL light indicates an error code has been recorded. The light is turned on if the error happens more then 2x during a normal run condition. The light will remain on until 2 things happen.

1) The car has several sucessful run cycles without the error happening again.
2) The error code is cleared manually.


Just replacing the sensor does not immediately clear the error. It just stops it from being recorded. If you don't clear the error after replacing a defective sensor, the CEL will turn off by itself after several error free cycles. Depending on how much you drive, that could take a week or two.