I used the SMP brand with good results (Standard Motor Products) on our 95 and 97 EJ22.

These knock sensors use a vibrating Piezo Electric element to generate a signal to the ECU as shown in this picture.

That is why mounting torque is important.

I was wondering about the purpose of this mechanism.    Thanks for informing me on the fundamentals of this unit.  I torqued it down well twice.  Still having the same timing off problem.

I believe the cable from the KS is shielded, maybe you have a grounding problem.

excessive carbon buildup in one or more combustion chambers could lead to excessive knock. maybe pull and examine the spark plugs for carbon???

I'm about out of ideas.....

 

Make sure the pins did not push back out of either of the connectors and are not making a good connection. That happened on our 97 EJ22. I just removed both pins from their connectors and plugged them together and wrapped them with tape.

I could take some pics; tried to push the connection together again today, drove 200 miles.  Power issue seems to manifest at start ups and low speed.

Here is an image of the connector:  https://i.imgur.com/XigiKkW.jpg

 

What's the chance that it could have been damaged from the other end where it comes from when I pulled it out?

Edited October 21, 20205 yr by ThosL

It is possible that the wire (on the harness side) is broken from the terminal in the connector. I've seen it a few times.

9 hours ago, Rampage said:

It is possible that the wire (on the harness side) is broken from the terminal in the connector. I've seen it a few times.

That was what I feared from the beginning which makes it a real mechanic's job, but cel went out yesterday, so will keep monitoring it.

In your photo the wire is covered with plastic Wire Loom to protect the insulation on the wire from rubbing on anything. What happens is the Wire Loom and the insulation on the wire get hard from heat off the engine. When the wire is bent the insulation will crack in a circle around the wire. The insulation is hard and does not compress so the wire will stretch and get thinner and more prone to breaking. Wire Loom serves its purpose if it is not overheated. I have removed the intakes on a lot of 90s and half the loom under the intake is laying on the engine.

I got an oe knock sensor today, and put it in with some difficulty again.  Will see if that was it.  

New unit made all the difference!  Lots of power now, no problems.

Two different units on ebay:  The OE unit:  https://www.ebay.com/vod/FetchOrderDetails?itemid=192926413511&transid=1781703698009&ul_noapp=true

 

Bad unit:  https://www.ebay.com/itm/Detonation-Knock-sensor-for-1997-1999-Subaru-Legacy-2-2L-2-5L-KS96/353064994578?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

42 minutes ago, ThosL said:

New unit made all the difference!  Lots of power now, no problems.

COOL.. Let's hope it lasts a long time.

That shows the difference in quality. The bad one was probably sending signals from vibrations instead of cylinder knocks.

3 hours ago, ThosL said:

New unit made all the difference!  Lots of power now, no problems.

Two different units on ebay:  The OE unit:  https://www.ebay.com/vod/FetchOrderDetails?itemid=192926413511&transid=1781703698009&ul_noapp=true

 

Bad unit:  https://www.ebay.com/itm/Detonation-Knock-sensor-for-1997-1999-Subaru-Legacy-2-2L-2-5L-KS96/353064994578?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

The cheap knock sensors work often times but expect some rates of issues.

That was a good call to try another sensor. It’s easy to think “already replaced that, what’s next”. 

https://i.ebayimg.com/images/g/ngQAAOSw5Xtc5ux0/s-l1600.jpg

 

The claim on the unit I put in yesterday was it was OE Subaru, not sure if that is accurate.

 

You don't have to pay $90 for an OE knock sensor like Auto Zone quoted.  Absolutely no reason to.

There were other OE units on ebay for under $20 delivered.  

If a mechanic were to charge $90 or more for one and then another $75 plus for installation, that would not be fair.

We are over 20 years into when these cars were produced, parts also are old, even if OE and new.  If I were selling them, I would be looking to get what I could for them before the market for them collapses.  

Edited October 23, 20205 yr by ThosL

At least the spelling on the sticker is correct.

It says Parts like it should, instead of Rarts like that one some time ago.

9 hours ago, ThosL said:

 

We are over 20 years into when these cars were produced, parts also are old, even if OE and new.  If I were selling them, I would be looking to get what I could for them before the market for them collapses.  

Sometimes it works like that. Sometimes the price goes up for good reasons.

As demand decreases, the supply is also decreasing in some ways - in availability, in logistics (how many places have them, geographic clustering, and how many they have in hand, shipping times), OEM specific supply, etc.  If this functional supply is deceasing faster than demand then economics 101 supply and demand curves show us how price can go up.

It depends on the parts, how many there are and prospective demand.

Sound 2.5 engines from the 90s, etc. are hard to find, the 2.2 engines seem to be more available.