Knock sensor or O2 sensor

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Mar 20, 2020
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Grove, Ok
I recently had the engine light come on. The parts store plugged in their reader and said the left bank is running lean and thought it might be an O2 Sensor. Before I order replacements, could it be a knock sensor issue?

Thanks

Robert
 
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Gilbert, AZ
Your best bet is to grab a voltmeter and check the resistance of the O2 sensors. The FSM calls for 5-6.5 ohms anything more is a bad O2. Not sure if you can test the knock sensors the same way but start with the O2 sensors as they send a signal to the ECU to lean/rich a fuel mixtures based off what they are reading.
 

FMC80

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What year is your cruiser and how many miles? When is the last time the O2 sensors have been replaced?
Agree with Scott. Get after the low hanging fruit first. Knock sensors are generally good until f***ed with.
 
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Olathe, KS, USA
I recently had the engine light come on. The parts store plugged in their reader and said the left bank is running lean and thought it might be an O2 Sensor. Before I order replacements, could it be a knock sensor issue?

Thanks

Robert
If it's running lean it's not a knock sensor.

It is most likely a O2 sensor but it needs to be properly diagnosed as @OffRoadScott stated.

Understanding what the sensors do is important.

Knock sensors tell the computer to adjust timing. This doesn't affect air/fuel ratios.

There are other things that could cause this such as vacuum leaks or a bad ground or connections on a O2 sensor.
 
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If it turns out that I need to replace the O2 sensors what the best source to buy from. I see Wits end does not currently have them in stock.

Thanks
 

FMC80

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Need more info. O2 sensors are on back order, discontinued, hard to find blah blah blah. You have to find replacements based on your specific model cruiser.

What year cruiser do you have? Do a Google search using key words like, “O2 sensors for 1FZ-FE Ih8mud” “199x Land Cruiser O2 sensors Ih8mud”

There are so many threads about O2 sensors and their replacements here. When you learn to how to more effectively use Google, it will aid you in your search.

Here’s a couple to get you started.

 
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If it turns out that I need to replace the O2 sensors what the best source to buy from. I see Wits end does not currently have them in stock.

Thanks
Toyota does not sell both the o2 sensors anymore, they sell the one with the longer pigtail which you can use in both sides. You can get a NTK or Denso O2 sensor from Autozone, make sure it is the one with the longer pigtail.
I went with the Bosch O2 sensors but there are mixed reviews on MUD about the Bosch ones.
 
Joined
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Messages
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Need more info. O2 sensors are on back order, discontinued, hard to find blah blah blah. You have to find replacements based on your specific model cruiser.

What year cruiser do you have? Do a Google search using key words like, “O2 sensors for 1FZ-FE Ih8mud” “199x Land Cruiser O2 sensors Ih8mud”

There are so many threads about O2 sensors and their replacements here. When you learn to how to more effectively use Google, it will aid you in your search.

Here’s a couple to get you started.


I did the repurposing of the newer O2 sensors and mine only lasted a few years, in that few years it saw low mileage and never threw a code.
 
Joined
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Messages
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I recently had the engine light come on. The parts store plugged in their reader and said the left bank is running lean and thought it might be an O2 Sensor. Before I order replacements, could it be a knock sensor issue?

Thanks

Robert

I just read your post again. I would go to partsouq.com and input your VIN in the search and it will bring up all the factory parts in a schematic. I have found it easier to locate parts by clicking on the "group" tab, the O2 sensor will be under exhaust - lamda sensor.

The schematic will look something like this.

MEQ183G.gif
 

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