[Atomic1]

I know the older (pre 2000ish) knock sensors had issues cracking and throwing codes. Does anyone know if this holds true to a 2002?

I just had headgaskets replaced two months ago and now I'm suddenly getting a P4035 code (knock sensor wiring). The connections are secure, orientation of sensor is per the manual, and it doesn't look cracked. Not sure if I should just spend the $85 on a new sensor or look into something else.

 

[Peaty]

First I suggest you torque it down to the specs, if that does not work I bet it's time to replace it.

http://www.scoobymods.com/knock-sensor-location-info-t4039.html?t=4039

 

[Tau137]

Check the wiring, check the continuity, check the resistance (around 0.5MOm, iirc). And the sensor itself. Be careful of overtightening - these things break easily.

 

[TexasForester]

check ebay for a used or new knock sensor. I got one for much less, $25 as I remember. See following link.

SUBARU LEGACY 2.5L 1999-2005 KNOCK SENSOR A190 : eBay Motors (item 370314515464 end time Mar-02-10 14:48:05 PST)

good luck