The code 52 is one of the highest priority codes as far as the ECU is concerned. There are only a few which will cause the ECU to run in the fail safe or limp mode you're experiencing. There are also very few which will actually cause the check engine light to turn on; As such, it's possible to have codes which indicate problems which significantly impact the vehicle's functionality which the ECU doesn't tell you about. So, it's good practice to check for codes on a regular basis.
I'm not going to say it'll fix your issues... but it should have a significant impact.
The wiring is just as often at fault as the knock sensor. If the knock sensor is intact the wiring may be the more likely culprit.
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