Cause
Damaged knock sensor wiring
The wiring to a knock sensor damaged, so the signal is degraded or lost. These sensors produce a very small signal and usually run in a screened cable, which makes their wiring more sensitive to damage than most.
A damaged screen lets interference in, and the module reads that noise as detonation — so it retards timing on an engine that is not knocking, and the complaint is a loss of power with no mechanical fault. A broken conductor gives the opposite: no knock detection at all, which is more dangerous because real detonation goes unanswered. The harness runs down the back of the engine in heat and vibration — inspect where it crosses a bracket, and repair the screen as well as the conductor, or the noise problem replaces the open circuit.
Typically a moderate job.
Codes this can cause (1)
Codes where this is a likely explanation first, rather than merely a possible one.
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