Denso234-9022 Air Fuel Ratio Sensor

My car is a 2009 Toyota RAV4 with a 2.5L 4-cylinder engine. I believe this Air/Fuel Sensor, product # 234-9022, is a piece of Original Manufactured equipment because it fits perfectly and it looks the same as the one it replaced. Replacing this item was not difficult. It was pretty easy to screw the sensor off the gas pipe in front of the engine and I was able to do it above the car and quickly. But originally I didn’t intend to replace this sensor. I got an error code from my OBD2 Car Diagnostic Scanner that showed "Code: PO137, Define: O2 Sensor Circuit Low Voltage Bank 1 Sensor 2". I researched the issue on YouTube and other Toyota online forums. I found out that I should replace both Sensors 1 & 2 at the same time. So that was what I did. Sensor 1 was the Air/Fuel Sensor and Sensor 2 was the Oxygen Sensor, product #234-4622. I had a really hard time unscrewing the flawed Oxygen Sensor out of the gas pipe due to a lack of space to rotate the ratchet. In addition, the connector was too high to reach with both hands from under the car, where the sensor is located. You would need one hand to jam a flathead screwdriver into the connector to release the hook, and the other hand to pull the wire out of the connector. There was not enough space for two hands to do this from under the car! Luckily I had my brother helped me out. He stood next to the car and reached down with one hand to take a screwdriver to release the wire from the connector, and I pulled the wire from under the car. After that, installing the new sensor was a much easier step.As soon as I replaced both sensors, the error code went away. Also interesting to note: some online forums I visited have indicated that Oxygen sensors and Air/fuel sensors tend to last about 10 years. That's exactly how old my car is when the error code showed up.I learned about this repair routine from others on YouTube and other online forums, so I appreciate those people's videos and inputs. This DIY repair saved me at least $500 compared to having to leave the car at a repair shop or dealership. As such, I took the time to write this review in the hope that I'd paid my money-savings forward to someone who might be facing a similar problem.

This resolved an issue I was having with a P0138 code on a 2011 Sienna V6 - O2 sensor bank 1 sensor 2. I had already replaced O2 sensor 2 earlier and the inter webs suggested that the Air Fuel sensor was probably at fault (bank 1, sensor 1).So, I ordered this part. I’m unsure if this wasn’t really for Bank 2, sensor 1, but they’re the same sensor with slight differences on wire length and accoutrements. Needless to say, it fit and resolved my codes.The DIY aspect is rough on this one due to space and visibility. Removal of the old sensor is rough. I soaked it with PB Blaster overnight and then used a 22mm crows foot on a 12” articulating socket wrench that I then extended with another 1ft pipe fitting around the wrench. It basically rested in line with the exhaust and with the few inches I could move in any direction I was finally able to free it.Ideally, it should be a 15 minute swap… but you’ll spend twice that just figuring out how to get to it and put everything together to break it free. Conversely, putting the new one in and plugging in, securing the wiring, etc will take two minutes.

I had p0136 and p0138 codes on my 2012 Toyota Rav4 2.5L engine with 139000 miles recently. Tried clearing the codes, and both codes kept returning so I decided to fix it myself. Now codes p0136 & p0138 stear you to the Bank 1 Sensor 2 O2 sensor. After researching these codes for my vehicle,I found a lot of comments online that said the problem was Bank 1 Sensor 1 Air Fuel Ratio sensor and NOT the Bank 1 Sensor 2 O2 sensor, so I decided to replace the Air Fuel Ratio sensor with this Denso # 234-9022 part. First off, I sprayed the 4 bolts on the Heat shield above the Exhaust intake and the sensor itself with PB Blaster the night before. The 12mm bolts easily came off and I removed the heat shield. The sensor also spun off easily using my Tekton 3/8" drive 7/8"(22mm) offset socket I also purchased from Amazon. After applying the included anti-sieze compound to the sensor, I screwed it on and torqued it to about 35 ft-pounds and reinstalled the heat shield and torqued the 4 bolts to about 12 ft-pounds. I cleared the codes with my obd-ii scanner, and test drove it to get all monitors to display ok and ready, and I have no codes pending and no check engine light after 2 days and 100 miles of driving. So, this part worked excellent in clearing my check engine light even though my scanner said to replace the O2 sensor!

I wanted to share a quick recommendation regarding the P0138 engine code related to the oxygen sensor in your vehicle.Based on my experience, when the P0138 code appears, it often indicates an issue with the oxygen sensors. In such cases, it's advisable to replace both the upstream and downstream oxygen sensors simultaneously. This approach ensures optimal performance and helps to resolve the issue more effectively.