Glenn
If your mechanic can check the codes, he[she?] ought to be able to specify which knock sensor it is that is causing the problem.
Code 22 is for the RH knock sensor, and code 28 is for the LH sensor, so it should be obvious.
I am not sure exactly where they are fitted, but there is one for each block of cylinders.
They must be really easy to fit. The US ones are sure to be the exact same, and 1stSubaruParts will post them to you.
Joe
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