i recently did a 3vze swap on my friends 95 4runner due to blown head gaskets and he let the water sit in the cylenders.so he got a used engine but the engine they gave us was a 88-91 i switched everything but the knock sensor i made a jumper for the 88 round to the 92+ rect but i keep getting code 52 knock sensor are the sensors putting out a different signal . should i just have him get the intake gasket set and a new or used 92-95 knock sensor

 

Can`t you take the knock sensor out of the original motor and put it in the new one ?.

 

already gave the engine back as a core

 

Try going back were you took the core and tell them you forgot to remove the knock sensor, and see it they will give it to you. Its worth a try, and it might save him a few dollars.