52 is the biggie of those codes. I'd attend to that first. Typically it's a wiring issue, not the knock sensors themselves. Look again in the FAQ section for a thread on knock sensor problems or knock sensor rewiring.
Also, check if the mixture screw on the KVAFM has been tampered with. If it hasn't there will be a press fit plug hiding it in its cylindrical housing... otherwise the plug will have been drilled out.
***Could someone post a picture of the mixture screw on the KVAFM and also check if there is a two digit number near it? It should be the same as the VAFM when it comes to adjustment (see the new FAQ on this).
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