This is for a '94 Corvette.

I know there is a separate code for the KM failure, but I replaced the sensors and all the wiring checks out ok. DTC 43 keeps coming up.

There is an exhaust leak under the car, but I will be replacing the exhaust anyways. I can tell by the way it runs that timing is being pulled out.

If the KS sees a lot of knock, will the DTC show up? Will adding an LT4 KM help by reducing sensitivity?

Thanks!

 

Are you using the correct sensor? No DTC for observing knock, no matter how much, so the LT4 KM would not help.

 

That's what I needed to know, Thanks!

Yes, using the correct sensors. The only thing I can think of now is the problem is the PCM.

 

Did you run an electrical check on the knock sensor circuit? Do you have 5V between the harness wire and the block, with the wire off the sensor (the Corvette has two knock sensors - you have to check both of them). With the wire still off, measure the resistance across the sensor from the terminal pin to the block. Should be in the range of 3,500-5,500ohms. Then reconnect the harness wire and measure the voltage from the wire to the block - should be in the range of 1.5-3.5V. Any thing outside that range sets DTC 43. The last voltage number is for an F-Body with a single knock sensor on the circuit. The voltage may be slightly different on the Corvette because of the two knock sensors being wired in parallel.