Hi guys,

Since I bought my MY95 WRX RA about 10 months ago I've had a constant issue with detonation. It would happen whether the weather was hot/cold and was driving me insane. It got to the point where I had to lower my boost to 0.7bar to prevent it.

Well last weekend while reading through the factory manual I came across the knock sensor diagnostics, hmmm, it basically said that if you get det, check the knock sensor.

I then swapped my knock sensor with the one in my friend's WRX but it didn't work (check engine light came on with code 22), put mine back in and went to test it just to see. Believe it or not, the det was gone. At the moment I'm running 0.95bar totally det free.

My advice to everyone getting det on the stock ECU, please have a go at replacing your knock sensor and making sure the knock sensor connector is clean. I think my contacts were slightly corroded/dirty so the ECU could see the knock sensor fine but not get the proper signal out of it. BTW my car never ever attempted to retard timing so that was probably a clue that it wasn't seeing the det.

 

You also need to make sure the engine block is clean where the Knock sensor
sits and you torque it up to 24 Nm.