1990 Suburban .....Code 42 Help
 

I just finished installing a new gm crate 5.7 engine in our suburban. I replaced the knock sensor. When I did I used the pink pipe tape around the threads..Could that have isolated the sensor causing a bad ground ?

Re: 1990 Suburban .....Code 42 Help
 

here is the beast

Re: 1990 Suburban .....Code 42 Help
 

I would say you are correct. Pretty sure they are installed "dry". Since it is pipe thread, it seals itself.