Code P0325 please help (knock Sensor)

[Gtfourever]

Hello everyone, I have a 99 ES300. When I bought the car it had a check engine code, ended up being both knock sensors so I replaced them both along with the harness. I took it for a test drive and within 2 miles the codes pop up again 😔. I used aftermarket parts so I figured that was the problem. Then I repurchased the parts all with OEM this time, I get it all back together and again 2 miles down the road and code P0325 pops up car again goes into limp mode. So to sum it up I replaced the knock sensors and harness twice with NO cure to the problem. Could I be missing something or does this problem run deeper? Has anyone else experienced this problem?

[gbhrps]

Gtfourever,

The best advice anyone could pass on to a backyard mechanic, is to never throw parts at a problem, unless you know for a fact the original parts are bad and the cause of the     issue.

Certainly, read the codes to identify the problem area and have an idea of what you are up against. But then before buying parts, check with a good independent mechanic you trust, to verify if this is the issue, because something else could cause the same symptoms.

I did some research and found several people with the same model, year and issue, who filled the gas tank with premium fuel and ran it. In both cases after about half a tankful of premium the CEL light went out and the cp0325 code disappeared. Others used a hack fix, by pulling the connector that carried the wiring from the two knock sensors to the ECU. They cut the wire to the bad knock sensor and taped it up, and then spliced the other end of the same wire to the good knock sensor wire where it enters the connector to the ECU. Essentially the one good sensor would supply the info the ECU needed for the two knock sensors. There was a pictorial about the hack fix, and cheaper Toyota parts that had a Lexus sticker over the Toyota one and cost much less as well.

Unless someone else has the ultimate answer for you, you need to do some research. Good Luck!

[luma99]

 Use premium gas ONLY and if code doesn't  go, disconnect the knock sensor harness and bridge the 2 sides of the wire pins with a thin flexible wire in and around the pin separator and plug it in again.

[Kris.hyd]

as I understand knock sensor code iwould shows up when the engine is knocking. So how do we know if the code received is because of the bad knock sensor or bad wiring or because engine is knocking. Purpose of knock sensor is to detect knocking of engine. Everywhere in the net I see that if p0330 code is received then knock sensor needs to be replaced. However if the engine is having some issue, then ho do we know. 

[luma99]

Hey Kris, did you check the harness that goes to the computer?,(from the computer to the knock sensors are 2 harnesses) check continuity with a volt meter, also it might be the computer itself. Now, this option a lot of people will disagree with me; if the car has high mileage, check also the timing belt, including the tensioner. Good luck.

[OU1]

A knock sensor is used to stop knocking of the motor when it happens.  Reducing rough idling and what not.  Not using the correct fuel could be the issue.  Most posts and videos I've watched on this say it's usually the knock sensor wiring that is the culprit.  From what I understand knock sensors don't usually go out unless the motor has a lot of miles on it.  I suggest if the correct fuel does not solve this problem then start looking at the wiring and connectors.