Hello, I just purchased a 99 RX300. When I purchased the vehicle, it was throwing multiple faults and would die when driving and go into limp mode. PO did not know that the two grounds on the intake were not connected at all. Once connected, the issue was fixed with misfiring and dying. Now when driving at about 40 MPH maybe 2-3 miles, the vehicle will go into limp mode and faults P0325 P0330 and P0171 will come on at the same time. I have never dealt with knock sensors, but is it common for both to fail at the same time? Is there another wire/ground for the sensors that could possibly be the issue?

 

Welcome to club Lexus. Please look at the sticky threads [the fixed threads which don't go away and occupy the top 1/4 or 1/3 of the threads.

Knock sensor(s) typically fail around 150K miles.

Alos use the "search" feature and use key words "knock sensor" and you will find lots of information. We also have a DIY for proper fix and couple of threads on how to kludge, but since you are getting fails on both the sensors they may not work for you. Do keep in mind that an error is not a guaranteed fail of the sensor ... it means the ECU is getting bad info and it can be the wire or supply or ground.

If you want, please share why you bought the vehicle with an error code, without understanding it. The fix at the shop [dealer or otherwise] is pretty steep ~8hrs labor and parts on top. It can exceed the street value of the vehicle unless you are a mechanic or an avid DIYer.


Salim

 

Hello, thanks for responding, I was using the search function prior, but maybe I was not using it as intended because I couldn't locate anything. When I purchased the vehicle, it only had faults for misfiring on all cylinders and shift solenoids. Those were fixed with the grounds on the intake. I purchased it non-running for $400 with 143,000 miles. I also will be working on the vehicle myself. The knock sensor code and system too lean bank 1 did not pop up until I was able to get it running. I will try and search threads again and see what I can find.

 

Use the last thumbnail "search this forum". If you wan you can use advanced search but all unto you.
Even with the search you will be inundated with threads as Knock sensors is mentioned too many times.

You got yourself a deal and a project.

Based on my experience, RX likes OEM electronic parts and you should watch out for counterfeits or sub-standard repackaged items. Believe me there are plenty of those being sold for the most popular SUV.

Also remember to take your VIN for purchase of parts. Knock sensors are different based on model/yr.


Salim