2006 Camry Altise Limited V6
Having some issues diagnosing a reoccurring knock sensor error light, occasional pinging (in low revs/uphill) and complete loss of power.

The full picture:
Around 5000km ago I had the timing belt changed and the front and rear gaskets due to a crack. After the repairs, the engine was also tweaked as revving too high in idle. The car drove well for around 1000km before an error code for faulty knock sensor appeared and the car began pinging when accelerating.
Knock sensor was replaced and around 40km later the car started pinging again and cut out with full loss of power on a junction as I was trying to accelerate (pretty dangerous).
Mechanic received the car after being on the tow truck, managed to start the car the following day without issue and couldnt get it to repeat the loss of power.
After driving around a while the knock sensor light reappeared and mechanic tested for faulty sensor - all seemed ok. Reset the error.
Took the car home and out to the shop, the error code is now back again and possible faint knocking sound when accelerating up hill.

Any ideas why the error code is coming back on?
Could there be an electrical fault?
Other issue in the engine?

Thanks in advance for any help!!

Mike

 

There are two knock sensors. Which one does the code reference and which one was replaced?

Any change in type of fuel being used?

 

@toyomoho
Knock Sensor "Number 2" was initially replaced after the error code came on. When the light came on again the mechanic tested the new knock sensor for faults and also replaced the "Number 1" knock sensor. The error code still appears for Knock sensor 2.

I have been running the car on premium fuel only since the engine light appeared.

 

An issue is accessing the sensors is very time consuming.

The test procedure is to swap the sensor wiring and ECM inputs. Here sensor 1 would be wired to the sensor 2 wiring and ECM input and sensor 2 to the sensor 1 wiring and ECM input. Then operate the car and see what happens. If the same sensor code comes up as before the issue is the wiring or ECM.

If your mechanic has the right scanner they can check the sensor output waveform in real time bypassing the need to wait for a trouble code to be generated.. Toyota has specific criteria for what the waveform should look like, its frequency, period, etc. Toyota dealers have diagnostic equipment to do this.