Review on 🔌 Denso 234-4622 Downstream Oxygen Sensor: Black, 4-Terminal Plug – Ultimate Efficiency by Luis Adu

My car is a 2009 Toyota RAV4 with a 2.5 liter 4 cylinder engine. I believe this oxygen sensor is an OE part (P/N 234-4622) because it fits perfectly and looks exactly like the one it replaced. The item itself is cheap but it was difficult to replace it myself. It was very difficult for me to unscrew the original sensor from the gas line as there was no room to turn the ratchet. In addition, it turned out that the plug was too high to retrieve with two hands from under the car where the sensor is located. You will need one hand to insert a flathead screwdriver into the connector to loosen the hook and the other hand to pry the wire out of the connector. There wasn't enough room for two hands to do it under the car! Luckily my brother helped me. He stood next to the car and reached down with one hand to take a screwdriver to pry the cord out of the connector while I pulled the cord out from under the car. After that, installing a new sensor became much easier. Also note that the fault code that prompted me to replace this sensor was "Code: PO137, Definition: O2 Sensor Circuit Low Voltage Bank 1 Sensor 2". I also replaced bank 1 sensor 1 at the same time. Bank 1 Sensor 1 is located on the front of the engine and is called Air/Fuel Sensor, part number 234-9022. The reason I replaced both sensors was because I was told by a mechanic that failure of sensor 2 is usually caused by failure of sensor 1. When sensor 1 fails there is too much or too little oxygen. engine, and this condition creates too much or too little oxygen, which escapes from the engine, which in turn causes sensor 2 to indicate a fault to the computer. Therefore, to completely solve the problem, both sensors should be replaced at the same time. That's exactly what I did. As soon as I replaced both sensors, the error code disappeared. Also, some online forums I've visited indicate that oxygen and air/fuel sensors typically last around 10 years. That's how old my car was when the error code came up. I learned about this repair procedure from others on YouTube and other online forums, so I appreciate these people's videos and contributions. This DIY repair saved me at least $500 compared to taking the car to a garage or dealership. So I took the time to write this review in the hopes that I've paid my savings upfront to someone who may have a similar issue.