st got this car and have been fixing all the little issues.

when the car is cold it runs and idles good...not great but good but as soon as it hits closed loop mode when the car is idleing esp. when in drive its starts to stumble and surge.

i have been checking everything but just my luck the check engine light came on after about 20 mins of highway speed driving and then 5 mins later it turned off on it own. i had the time to pull the codes out today and it said code faulty 43 for knock sensor, ESC, or ECM.

i have ohmed out the knock sensor at 9 K ohms which is where it should be, i have 4.88 volts comeing form the sensor wire with key on, and i mesured the voltage with key on and sensor pluged in at 2.4 volts.

so that all checks out...im wondering what else i can do. i dont really wana change out the esc in i have too

thanks
joe

 

With it turning off on its own, that sounds like a shorted wire in the knock sensor circuit. It could be rubbing somewhere in the wire harness.