got a check engine light on, so got out code reader , bad knock sensor, so replaced sensor, cleared code , code came back , so decided to take off + side of battery for awhile , and see what happens , any other suggestions ? thanks

Known good sensor (or a new one).

 

Seem to be finicky about the route wire takes from sensor up under throttle body. Usually you can see the "clean" mark where the old path was.

 

Some folks say they are finicky about torque. I just make them snug. Never used a torque wrench and haven't had a problem yet.

Did you replace it with a new one or a used one?

 

What year/model are we talking about. There were some 90's knock sensors that were prone to cracking and were superseded with a new part. Old one's have a grey connector - new one's have a white connector.

 

GD

Is the code really for a bad sensor or is it a bad circuit to it?

97 2.2 awd, a/t. 174.000mi , sensor used, code reader says sensor or circuit , the one i took out was cracked real bad, if it is the circuit where should i look next, ? can the car be driven with no damage ? until i get a new one ,gray connector

Should be okay to drive without it in the short term.

 

I initially tried a used one as well when I had the knock code - didn't work.

 

$53 IIRC from my dealer. Best to get a new one.

 

GD

The ones I've bought were 80-100 my cost. Usually I have a used one though.

 

There was a thread a while back about whether this should be an OEM part or not. I don't know if it ever reached a conclusion.

that was my next question aftermarket or oem ? yes when i did a swap i should have replaced all sensors, but water under the bridge, just ordered a oem 47.00 bucks shipped to me, is there a easy way to change it ? boy it is hard to get in there,

Edited July 13, 200916 yr by 86subaru

A socket with a wobbly and some extensions.... it's not easy. I moved mine to an easier to access location closer to the bell-housing. It's not *that* critical that it be located in exactly that spot. It's sensing detonation and that's going to be felt more or less the same as long as you are near the center-line of the block.

 

GD

To check the wiring to the sensor just measure the resistance between the ends of the wire. The other end should tie to the ECU. There should be very little resistance between the ends. Also measure the resistace to ground to make sure the wire isn't grounded somehow.

ok, now today for aleast a few miles the check engine went out, then came back on,

the code reads knock sensor sensor or circuit bank 1

There is only the one knock sensor.

Is the engine pinging any? Any signs of mice taking shelter under your hood? (random fuzz sticks or straw stuck in corners)

no mice, i am reading what the code reader says, replaced knock sensor [ oem] check circuit , cleared code, and still getting knock sensor ???no pinging i give up going to take it to the dealer, found out problem broke end off trying to unplug it, now real problem,

Edited July 16, 200916 yr by 86subaru