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Lexus RX350 2011 FWD P2195 and P2238 Error Codes After Bosch O2 Sensor Installation

Model: Lexus RX350 Fault Code: P2195 Posted: 2019-07-04 09:25

Hi everyone, I'm new to this forum and seeking advice on a recurring issue with my 2011 Lexus RX350 (FWD, 78k miles). Around the 65,000-mile mark, the Check Engine light came on with code P0155 — indicating a faulty oxygen sensor on Bank 2. I replaced both upstream and downstream O2 sensors on Bank 2 with TKN sensors, and the car ran smoothly for several weeks. However, about a month later, the same system flagged another P0155 error this time related to Bank 1. I then installed Bosch OEM-style oxygen sensors (upstream and downstream) on Bank -1. After installation, two new fault codes appeared: - P2195: Sensor signal biased/stuck lean — Bank 1 Sensor 1 - P2238: Sensor positive current control circuit low — Bank 1 Sensor 1 A mechanic in Spain who helped with the installation noted that the wiring harness had to be physically modified — specifically, the positive wire on the Bosch sensor was not aligned correctly with the original factory plug. As a result, he manually reoriented the wires. My question is: Is it common for Bosch O2 sensors to have different pin configurations or wire placements compared to the original Lexus OEM (ND) sensors? Or could this be a sign that Bosch sensors are incompatible with the Lexus RX350's sensor harness? I'm looking for confirmation on whether OEM Toyota/ND sensors are recommended for this model, especially when dealing with P2195 and P2238 codes. Thanks in advance for your insights.

Related fault codes
P2195P2238
Comments (2)
Anonymous 2019-07-04 13:55

It's strongly recommended to use only Toyota OEM (ND) oxygen sensors on the Lexus RX350. Codes like P2195 and P2238 on Bank 1 Sensor 1 are frequently linked to improper sensor installation or mismatched wiring, especially when using third-party brands such as Bosch. The original factory harness is designed specifically for ND sensors with precise pinout alignment. A P0155 code on Bank 2 may indicate issues such as: - High resistance in the O2 heater element - Internal short or open circuit in the heater element - High resistance in the heater wiring circuit For detailed wiring diagrams and troubleshooting, refer to reliable sources like BBBind.com. Always ensure sensor polarity and pin configuration match factory specifications to avoid false codes or engine performance issues.

Anonymous 2019-07-04 14:22

Thanks @cj1 — I'll go back and purchase the original ND OEM sensors for Bank 1 and re-install them with proper wiring alignment. This should resolve both P2195 and P2238 codes.