Knock sensor

1994 TOYOTA PICKUP
177,000 MILES • 3.0L • V6 • 4WD • AUTOMATIC
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JOHNNY JEEPER
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Engine light code 25, had a certifiable mechanics three total. Replaced knock sensor, harness, valve cover, intake, plenum gaskets. Engine runs fine lack of power engine light on again at 2000 rpm. Second mechanic did these before second harness and knock sensor removed outside of block just below valve cover driver side to head second time light comes on knock sensor code 25 again. Third mechanic thinking resistor in ECM is not responding to knock sensor. Replace ECM light comes on for third time knock sensor code 25.
Feb 28, 2018 at 8:06 PM
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CARADIODOC
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Code 25 air/fuel ratio lean.

Appears you are looking for the wrong thing.
Feb 28, 2018 at 8:46 PM
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JOHNNY JEEPER
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Code was 52 not 25.
Mar 1, 2018 at 3:03 PM
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CARADIODOC
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Sorry for taking so long. That code is indeed for the knock sensor, but it doesn't say what type of problem it is. The way I'd approach this would be to connect a scanner to view live data and see what the Engine Computer is seeing. If there s no activity from the sensor, the best suspect is a broken wire going to the it. If there is a lot of activity, especially at a specific engine speed, a good suspect is a stretched timing chain slapping against the cover. Your engine uses a timing belt, so the next thing would be to look for any other metal parts that can clatter or rattle. Look at the valve train in particular, and even idler pulleys for the timing belt and belt-driven generator and power steering pump.
Mar 11, 2018 at 7:52 PM