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Knock sensor replacement

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the other week i got a CEL for the first time in my 99 outback sport, the next day it went off for a week or 2 but the other day it came one and it has been going on and off for the last week or so. I hooked it up to the machine and it said it was a knock sensor. I was reading other posts about knock sensors that said that accelleration and fuel economy was poor because the ECU adjusts the timing to make up for the sensor or something. My acceleration is fine and i've been on the same tank since gas was a buck 80! Im going to bring it to autozone and have them check the error codes just to make sure but can someone tell me how to test the knock sensor, and where exactly it is on the engine. And if it is infact a knock sensor malfunction how to replace it. is there a hayne's manual for 99 outbacks out there someplace? i couldnt find one at autozone. Thanks in advance for your help.

The sensor is on the drivers side, just behind the manifold where the gas cables connect. Its straight down, a single wire goes to the sensor which is about an 1" dia. A single 12mm bolt holds it on. Do NOT over torque the new one.

 

You can take a resistance reading, but I've not had much luck checking them that way.

 

Good Luck.

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dealer quoted $100, napa quoted 80, anyplace i can get this small piece of plasitc for less than 75 bucks?

Ed beat me to it... he's right, I just got one for $65 from 1stsubaruparts.com for the same problem you're having. Did the trick. -- George

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