Denso 234-9012 Air-Fuel Ratio Sensor 4 Wire, Direct Fit, Heated, Wire Length: 7.09â€

Works great no check engine light so far .

2009 Toyota Sienna: P0031 HO2S Heater Control Circuit Low (Bank 1 Sensor 1) Check Engine, VSC, Trac lights have been on, was not a loose gas cap (this time) This sensor can be replaced from below. I used a 7/8” wrench and a pry bar. - get the van up on ramps or jack stands - disconnect the wire. I used a small flat screwdriver to spring the retaining tab. - thread the closed end of the wrench over the wire, fiddle with the position till you can get some clearance. This took the most time. Finally I had a good line-up towards the front passenger wheel. - I stuck a pry bar in from the wheel well area and pried against the frame. Got a nice creak of rusty metal and it was not hard to remove and install the new one.

The product is exactly what i needed after installed... fix the codes on my sienna, thanks

Fit perfectly on my Toyota Sienna. Took care of my O2 Sensor light (its been a week). Today is 8/24/25

my mechanic tested the old ones before he put the new ones in and they were still working just fine so I was able to return these and get my money back but really appreciated that the mechanic said these are really good parts. Thanks.

UPDATE: I believe if you get a check engine light within a week or less of replacing this, you need to change your downstream sensor or replace your coils / spark plugs. This was documented on a youtube video I saw. I changed my downstream sensor and reseated my coil connectors and so far no code. My connector tabs broke off when replacing my spark plugs. I just replaced this on a 2004 awd sienna. Do this by removing y exhaust pipe from bottom. 6 bolts. After that there is plenty of room Buy the more expensive sensor removal tool that sits near the bottom of the sensor and not the one that looks like a socket. It will pop off easily. It was a slight challenge getting my socket in there but with the right removal tool and firm pressure it comes out easily

I read some of the reviews here on Amazon to be sure this O2 sensor was for Bank 1 Sensor on my 2007 Toyota Sienna Sienna LE 3.5 Liter engine. And it is. Purchased this 234-9012 Denso seosor and put it on the Sienna. I then drove the Van a good 25 to 30 miles and the check engine light did not came back on so, so far this O2 sensor has worked. You will need the offset O2 Socket to remove this sensor, the socket is a 3/8 inch drive. Removing the sensor is a challenge to unplug and plug this sensor back in. Y ou will need a good bright flashlight to see up in the engine to see the plug / connection, and a small screw driver to push the locking tab over on the plug's electrical socket that is holding the plug of the sensor in the electrical socket. Be patient. Located up inside the engine above the cross frame. Look on youtube to see where this O2 sensor is located, and also download engine diagrams and you will find online that show where all four O2 sensors are located on the engine.

Not originals 3rd party item does not fix problem with emissions

Replaced old part! No more check engine light! Big thanks to youtube, a mechanic buddy for fixing it for me.

Queda a perfeccion. Es la marca que recomienda toyota Aunque el precio es alto. Es mas barato comprarlo aqui que en otras tiendas.. No compres otro que no sea denso vas a batallar,

fit parfait pour Sienna 2004 juste a effacer le check engine apres et fini.

Great work for my Toyota Sienna 2009 3.5L code P0031 Oxygen Sensor Bank 1, Sensor 1 Denso 234-9012

Excellent (exact) replacement for 07 Sienna Sensor.