knock sensor question

[lil corb]

hello, First off I know what a knock sensor is and what it does. Ok, searching up it seems if the ECU doesn't detect a knock sensor that it goes into limp mode. I drove a car that threw a code and it turns out it's the not detecting knock sensor. Weird thing is when I drove it it pulled fine, no stuttering, or anything that would determine safe mode. Any ideas on why it didn't go into safe? maybe bad caps causing a bad knock signal? but not going into safe?

Car is a 91 AWD talon, completely stock, with a new motor.
thanks

 

[talonkev]

I've never gotten a knock sensor code but it wouldn't suprise me if the ecu pulls timing when you get one. I would start by reaching your hand back under the intake manifold, where the sensor screws into the side of the block. If you can feel gooey black tar like stuff seeping out of the sensor its time to replace it. If the black stuff is still solid make sure you connected its harness and didn't damage it when the new motor was put in. Usually when caps really leak they totally destroy the ecu and they car wont start at all or runs horrible, but not always.

 

[lil corb]

aight, I'll check today. Thanks for the info.