How many downstream o2 sensors is in a Cali 2001 4Runner Limited 4WD?

[sugjavier]

How many downstream o2 sensors is in a Cali 2001 4Runner Limited 4WD?

I've been getting the PO420 and wanted to finally change the downstream o2 sensors with Denso 234-4261 Oxygen Sensor. So far I only bought 1 and not sure if there's 2 total Downstream sensors. I have a guy who's gonna do it for a toblerone lol since I don't have the tools.

And if I do need to get another one, Am I replacing it with the right Model number for a Denso? I got that from Denso's website and Amazon says it fits.

 

[sportrunner2001]

theres only the 1 O2 after the cats. I searched the same part number and it says it fits. it also looks the exact same as the stock ones. If I remember right Toyota owns most of Denso and they made a bunch of the parts for our 4Runners so there shouldn't be any reason for it to be the wrong one.

also with the PO420, a lot of people have had problems with that code. I have it right now so I ordered the URD O2 simulator yesterday actually to get rid of it since my cats are a little messed up as it is.

 

[sugjavier]

theres only the 1 O2 after the cats. I searched the same part number and it says it fits. it also looks the exact same as the stock ones. If I remember right Toyota owns most of Denso and they made a bunch of the parts for our 4Runners so there shouldn't be any reason for it to be the wrong one.

also with the PO420, a lot of people have had problems with that code. I have it right now so I ordered the URD O2 simulator yesterday actually to get rid of it since my cats are a little messed up as it is.

What is that URD simulator? Do you plug it in instead of an o2 sensor? I just have one of those code readers and I can reset/clear the same stupid code every 400+ miles or something. I heard this code doesn't affect the car performance at all and can be ignored.

 

[hopdup]

It can be ignored unless you live in states where emissions testing is required. In PA your car will fail an emissions test if the c.e.l. is on.

 

[sportrunner2001]

What is that URD simulator? Do you plug it in instead of an o2 sensor? I just have one of those code readers and I can reset/clear the same stupid code every 400+ miles or something. I heard this code doesn't affect the car performance at all and can be ignored.

the simulator goes in between the sensor and where the information goes essentially. the o2 sensor remains in the exhaust but the plug on it gets plugged into the sim so the signal goes through it and then out to the other side of the original plug.

Heres a link to the product:
Underdog Racing Development

when the code gets thrown you won't notice any difference in power but a possible decrease in MPGs

 

[infamousRNR]

Denso part numbers

Please and thank you.

Part numbers for both 02 sensors??? For California?

 

[sportrunner2001]

[MENTION=102606]infamousRNR[/MENTION] amazon lets you enter your vehicle to search for parts. Im sure they're on there

 

[infamousRNR]

denso o2 sensors

thanks@sportrunner2001

although it lets me put in my vehicle it doesn't say anything about a CALIFORNIA one...

i got these two part numbers

Denso 234-9002 Air Fuel Ratio Sensor

&

Denso 234-4261 Oxygen Sensor

but neither indicates whether for upstream or downstream or for california emissions....

 

[TheDurk]

the simulator goes in between the sensor and where the information goes essentially. the o2 sensor remains in the exhaust but the plug on it gets plugged into the sim so the signal goes through it and then out to the other side of the original plug.

Heres a link to the product:
Underdog Racing Development

when the code gets thrown you won't notice any difference in power but a possible decrease in MPGs

No good reason to expect any change in mpg from a P0420 unless cats are plugged, and then you will have bigger problems than mpg.

 

[TheDurk]

thanks@sportrunner2001

although it lets me put in my vehicle it doesn't say anything about a CALIFORNIA one...

i got these two part numbers

Denso 234-9002 Air Fuel Ratio Sensor

&

Denso 234-4261 Oxygen Sensor

but neither indicates whether for upstream or downstream or for california emissions....

There were no California emissions in 2001, because the two-cat 'Cali' system was adopted nationwide in 2001 and ALL 4Runners used the same system.

Use the Denso site to get these part numbers. It shows upstream and down stream and California (in the appropriate years--'99 and '00 only.) The A/F sensor is always upstream.

Find My Part | DENSO Auto Parts

And, just to confirm, Denso O2 and A/F sensors sold by Amazon and others are identical to those sold by Toyota absent the red box and exorbitant dealer price.

 

[infamousRNR]

[MENTION=10169]TheDurk[/MENTION]
Thanks! i appreciate your response.
Amazon will take over the world with their low prices!
DENSO O2 SENSORS

 

[jgue467]

i got these two part numbers

Denso 234-9002 Air Fuel Ratio Sensor & Denso 234-4261 Oxygen Sensor

but neither indicates whether for upstream or downstream or for california emissions....

The air fuel ratio sensor is the upstream (before 1st cat) and the "02" sensor is the downstream (or after the 2nd cat) sensor. Luck :banana:

 

[sugjavier]

There were no California emissions in 2001, because the two-cat 'Cali' system was adopted nationwide in 2001 and ALL 4Runners used the same system.

Use the Denso site to get these part numbers. It shows upstream and down stream and California (in the appropriate years--'99 and '00 only.) The A/F sensor is always upstream.

Find My Part | DENSO Auto Parts

And, just to confirm, Denso O2 and A/F sensors sold by Amazon and others are identical to those sold by Toyota absent the red box and exorbitant dealer price.

I'm not sure if my 4Runner is Cali or not. All I know is that if I popped the hood open, there's a sticker under the good that says something with California. So I assumed it was a Cali lol.

Anyways, yep that's the site I used to get the part number. So just to confirm one last time, I only have ONE downstream o2 sensor correct?

Thank you guys for all your help!

 

[TheDurk]

I'm not sure if my 4Runner is Cali or not. All I know is that if I popped the hood open, there's a sticker under the good that says something with California. So I assumed it was a Cali lol.

Anyways, yep that's the site I used to get the part number. So just to confirm one last time, I only have ONE downstream o2 sensor correct?

Thank you guys for all your help!

Yes, ONE downstream sensor.

 

[jedreyling]

I searched the same part number and it says it fits.