Anyone now how to resolve code 43 on a 91 RS 3.1 ?

 

Typically the knock sensor is bad. Could also be the wire from the sensor to the ECM, or the ECM is bad (unusual).

To test:

Remove connector from knock sensor, measure voltage from wire to ground: needs to be between 4 and 6 volts (typcailly 5 volts). If not check wire and ECM, make sure MEMCAL is seated.

Measure resistance of knock sensor (center terminal to ground (block). Needs to be betwen 3300 and 4500 ohms. If not replace knock sensor. Do not use teflon tape on threads, do not overtighten (11-12 ft/lb).

RBob.

 

Thanks for the info I just picked this car up yesterday for my son. Got a SES light about half way home. Had about 6 codes in it, code 43 was the only one that came back last night. Drove it today, no SES light.

 

Where is this knock sensor on the 3.1?

I don't even know what it does, but seems like it helps with the EST. Would relying on mechanical only timing even need it to have a good knock sensor?

So if I disconnected the EST bypass and adjusted the timing would that be alright?

 

The timing aon a 3.1 is all controlled by the computer. The Knock Sensor tells the ECM if there is detonation going on so that it can retard the timing and stop the pinging.

If you disconnect the EST you won't be able to run full advance when you start revving up.

Go and read my post on your other thread so we don't hyjack this one.