knock sensor????

[92_240sx_95]

I have a 92 240sx with a 95kade. Just put a new ecu in the car today. The car is idling at 1500 rpms. I checked my tps and it was right so i adjusted my idle set screw and reset the tps but i could only get it to go down to 1100. So i checked the ecu and it popped a code 34. Looked it up and it said knock sensor. Just wondering what could cause a knock sensor to trip before i go and replace it. any help would be great thanks

[Infinitiguy19]

Only a bad Knock Sensor(s) could bring up that code, so replace it or them and be done with it. And no a bad Knock sensor will not affect idle RPM.

[92_240sx_95]

thanks. any idea why the idle would be so high??

[Klits562]

either you have alot of vacuum leak, or your timing is off.

[vmiramon69]

bad knock sensor messes up ur timing it makes ur car run rich
it retards ur timing up to 15 degrees