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Discussion Starter #1 (Edited)
Just took my Transit in for a Tranny filter and oil change and the Tranny shop checked the on board computer for any codes.
To my surprise they found a Knock Sensor code P0330.
They reset the code and did the Tranny service which cost about $400.00 due to that pan clearance issue.
They finished up the Tranny service in about two hours and took it out for a test drive and after which they
checked the computer for any codes and again found the Knock Sensor code P0330.
Strange thing is that there is no check engine light on the dash activated.

I had time that same day so I thought how hard can it be to change a Knock Sensor. So I open up my service manual and find
that this Knock Sensor is buried under the Lower Intake manifold and the connector pig tail way back between the Fire wall and engine!!! This is no simple Sensor change but instead a major tear down of the complete Air Intake subsystem.

Before I even begin to remove one screw or bolt I will have to check all of the wiring from the Sensor to the PCM input.
I have read that bad gas can cause this and since finding the code I have added about a quarter tank of new Shell high octane
gas. The day before I took the van in for the Tranny service I did add on bottle of Chevron engine cleaner that might have
triggered the sensor but until I use this whole tank of gas I cant be sure if the sensor is actually bad.

Since I have the new sensor I decided to measure it's resistance and both bank sensors measure ~5 ohms while being unmounted from the engine. If I can reach back behind the engine and do the same with the mounted sensor I am hoping it will read the same resistance value. If it is the same ohm value I will need to check the wiring all the way to the PCM.

Here is the part number of the dual bank Knock Sensor 7T4Z-12A699-AB.

Now I know why my MPG and power has been low for months which is a common side effect of a bad Knock Sensor circuit.
 

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I believe most knock sensors are piezo type elements to sense vibration. A bad one could possibly still read the same resistance value as a new good one.
 

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If you are taking off the intake manifold, then its a perfect time to change out the spark plugs because I am almost certain that the manifold needs to come off for the spark plug change anyway.
 

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Discussion Starter #4
Yeah, Also the PCV valve and clean out all the deposits inside the intake manifold from PCV oil vapor.

The worst side effect from having fuel injectors. Piezo devices can and do crack so it might show infinity resistance.

Here is a link on how to test Knock sensors:
https://us.autologic.com/news/piezoelectric-knock-sensors
 

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Yeah, Also the PCV valve and clean out all the deposits inside the intake manifold from PCV oil vapor.

The worst side effect from having fuel injectors. Piezo devices can and do crack so it might show infinity resistance.

Here is a link on how to test Knock sensors:
https://us.autologic.com/news/piezoelectric-knock-sensors

I have "low voltage" fault on both sensors 1&2 so decided to replace then and the harnes.

What should I ask the shop to do at the same time the manifold is removed ? Just to clean the PCB or can you please provide more specific description. TIA.
 
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