2001 tacoma 3.4l o2 sensor - which one?

$137 Denso 234-9001 Upstream Air Fuel Ratio Oxygen Sensor with 10.6” 4-Wire Harness, for Auto Trans Equipped Vehicles

https://www.amazon.com/Denso-234-90...keywords=Denso+234-9001+Air+Fuel+Ratio+Sensor

 

http://densoautoparts.com/find-my-part/vehicle-selection

 

Just checked Amazon and it looks like the A/F sensor is available,

$137 Denso 234-9001 Upstream Air Fuel Ratio Oxygen Sensor with 10.6” 4-Wire Harness, for Auto Trans Equipped Vehicles

Denso 234-9001 (if you have an auto). You can replace it and it may or may not help anything. If you go to a shop that does OBD2 diagnostic/testing (more than just "here's the CEL codes") they can see how the A/F sensor is behaving in regards to fuel trim and voltage. That could tell you if it's the sensor, or if there is another issue up-stream. It's either gonna take some investigation, or just buying new parts and hoping you get lucky.

 

I just replaced my AF sensor last week due to a P1135 code. It was a PITA as the nuts were completely rusted out and I had to file them down to get a wrench around them. It my understanding that the upstream and downstream sensors will throw different codes. I would also advise looking the part up on Desnso before buying on Amazon as their are different part numbers for manual and automatic. http://densoautoparts.com/find-my-part/vehicle-selection

 

Thanks again for the help guys!

I appreciate the links to Amazon but ive already ordered the part from them (9003 - manual) and then a week later they said it wasnt in stock and cancelled the order. The same part is still showing for sale by the same vendor but according to amazon as of today the part is not available.

Hence im wondering if i should shell out double the money to replace it soon or wait until amazon gets their shit together which could be who knows how long? Any recommendations? Am i gonna burn the cat up running too rich?

 

Check Ebay... same prices essentially.

http://www.ebay.com/sch/i.html?_fro...so+234-9003.TRS0&_nkw=Denso+234-9003&_sacat=0

 

Ok well the o2 sensor showed up and after working through the rusted bolt issue I installed the new one and the check engine light has been off since the first turnover. I think I got a little lucky on this one! I also managed to not mangle the heat shield, one bolt broke loose pretty easily and I was able to turn the heat shield around so I could access the other bolt easier. Ended up using vice grips to get it off, the bolt was rusted to the stud but the entire stud broke lose and came out fine. I replaced both studs with bolts and lock washers instead.

Thanks again for all the help and advice guys!

 

Hopefully that did the trick! It may take some time for the ODB readiness monitors to finish their test procedures; if they finish up and something doesn't pass, the CEL will come back on. Finger's crossed the new sensor helps.

 

Yeah I was wondering about that. I did disconnect the battery to switch the sensor, does that reset the ecu? I've driven maybe 25-30 miles since the swap but I'd imagine it will take longer than that.

 

Yeah, that resets the ECU. It depends on the driving conditions, duration, fuel level, etc, but the monitors will likely complete within a few days worth of driving.

 

Right on, thanks for the info!

 

Ok well I've driven a few days and a couple hundred miles and the check engine light hasn't come back on so I think that fixed it.

Is it still a good idea to do the a/f sensor since that's been almost 75000 also?

What kind of gas mileage are you guys normally getting? Is 16 - 17 the average or is it closer to 20?

 

I asked this exact question to the parts manager at my local Toyota dealership. He told me his previous job was at a wholesale manufacturer of Toyota parts. He said to wait till the car throws another code before replacing the other O2 sensor (downstream in my case).

 

Even though toyota recommends replacing these every 75000 regardless of a code or not?

I'm usually for the mindset if it's not broke don't fix it, but with electronic sensors it seems as if this may not always be the case?

 

Haha engine light came back on, same code. Figure it's the a/f sensor now that needs to be swapped out, right at about that 75000 mark...

 

@banketh, I know this post is 5 yrs old but what did you end up doing on this issue? I have the P0420 light and about to figure out my plan of attack. thinking of doing sensors first, and Cat as the last resort.

 

They have not been around since 4/2020

The first step is check for any exhaust leaks between the cats .

Allowing for exhaust to leak before the down stream sensor is able to read all the exhaust.

For what ever reason the ecm is reading to constant of a signal not enough difference .

Some get lucky changing the downstream sensor.

Good Luck!!

Good Luck

 

thank you! I will be checking for leaks first!

 

Good luck!

 

found this hole my worry is that it looks like I’ve had this for a while. Wonder why it triggered the code now.