Car is a 1998 JDM Version 4 STI, stock except Walbro pump and Japspeed decat downpipe.
I got my first solid check engine light the other day. When I checked the code it was 22, knock sensor. I cleared the code and went for a short drive, all was well. I read up a bit about the knock sensor, and thought maybe I should take out the sensor and have a look, maybe a clean up would help.
I found it a bit tricky to remove the sensor, just to the passenger's side of the throttle body one the TMIC is removed. When removed I saw it had a little crack in the side. I cleaned it up a little, put black tape over the crack and replaced it, but I suppose I need to get a new one.
1. Does the crack signify that the sensor is no good any more, or does it just cause trouble when the sensor gets wet? Apart from the CEL, the car does also appear to have been getting less mpg lately.
2. Has anyone used the Pulse 8 sensor?
http://cgi.ebay.co.uk/SUBARU-KNOCK-S...#ht_2955wt_905
It is significantly cheaper than the Subaru original at £42 vs £65 inc. shipping.
3. Finally, does anyone have any good tips to ease the removal / installation of the sensor? There seemed to be all sorts of coolant hoses in the way, and I didn't want to disconnect them in case I got bubbles in my coolant, or spilt coolant all over the place. In retrospect it would have made matters a lot easier to disconnect them and get them out of the way, but I wasn't sure if they'd be still full of coolant after the car was standing a while.

Thanks a lot, Tom

 

yep that sensors shot,how about
http://cgi.ebay.co.uk/Impreza-WRX-ST...item3f04f1b4b9
fitted mine with a bit of a fiddle without taking off coolant hose ,trick is to use the wire on the sensor to pull off the sensor and bolt as one mate.not difficult only fiddly,

 

just read apparently the area of the knock sensor cord must
be positioned at a 60" angle relative to the engine rear.??
and the 12mm bolt must be tightned to 24nm/17.4 lb ft too mate for it to work correctly

 

Thanks a lot. I found that part before the cheaper one. Due to unemployment I was hoping to save the £23 odd and buy the Pulse 8 one.
Thanks for the tips, Tom

 

Anyone have any comments on the Pulse 8 sensor?

 

If the KS is fudged, it is possible that it is sending incorrect info to the ECU ie that it is detecting knock. This will in turn cause the ECU to pull the timing to protect the engine.
I personally, would buy the OE item, or at the very least a good used OE item.

 

Well I decided to buy this one
http://cgi.ebay.co.uk/ws/eBayISAPI.d...#ht_1315wt_905
It was a decent enough price, supposed to be low mileage OEM, immaculate feedback etc. Car almost immediately got CEL (solid) once I got stuck in traffic today, so had to be done.
Hope it's here soon and does what it says on the can.
Tom

 

how did you get on with this?
did it solve your problem?
cheers
andy

 

Hi andy, so far so good. No CEL, seems to be all working well. Nothing bad to say about platinum-imports-uk quick delivery and part seems to be good. Cheers, Tom

 

oh thanks for that i will def get a new one then
cheers
andy