Not sure where to post this, but I thought you guys might have some answers. I have been having trouble with my knock sensor going crazy. I am most definitely sure I am not getting any knock. I just rebuild the engine and am running a larger cam and headers. When I scan the ECU I get an error code #43 esc failure, which is the knock sensor. When I first start the car its fine, but then after about 30 seconds the check engine light comes on and I get that code. Then my BLM is constant at 128 and my O2 readings stay relatively constant. I also have new O2 sensors. So do you guys think it could be that my knock sensor is either broke or picking up too much noise? Should I just replace it with the LT4 sensor? Thanks for any input you can give me.

 

Code 43 indicates that the PCM is not getting proper indication from the knock sensor. Could be a bad sensor, sensor not making good contact with engine block, open wire to sensor, or sensor wire shorted to ground or to another wire. Code 43 is not an indication of knock. When this code is set the PCM will retard the spark to a preset value to protect the engine. The LT1 and LT4 sensors are the same; however, the knock sensor module, which plugs into the PCM is different. The LT4 module is less sensitive to extraneous noises.

 

what yr? 92-93 lt1s have a different knock sensor that is not interchangable with the lt4 sensor.

 

It is a 94. Sorry I meant knock module. I put a brand new knock sensor in with the engine rebuild. I will go through and make sure all of the wiring is good. I think I read something that if you over tighten the knock sensor it can mess it up. Is this true? I did not really crank on it, but I might try loosening it up a bit. From what I have looked up the LT4 module is less sensitive and is a good idea to have when you are running headers or a bigger cam.

 

The knock sensor has to make good electrical contact with the engine block, the threads should both be clean on the sensor and on the engine block, do not use plumbers tape as that will mess up the electrical path. Too much torque will damage the sensor, and too little torque will allow water leaks, and make poor electrical contact.

 

Oh you know what. You mentioned not to use tape, and thinking back I MIGHT have put some sort of sealant on it not even thinking about it. I will have to check it out this weekend to make sure though. Thanks for mentioning that, hopefully that is the problem.

 

So I was working on the car a bit today. I decided to use tunercat to erase the code 43 esc failure. When I erased it the car ran better and the BLM was actually changing like it should. I was also getting almost no retard at all, only at higher revs and it would be 1-2 degrees. Am I going to run into problems by disabling the code 43? Is it actually disabling the knock sensor?