2004 Toyota Sienna P2242 O2 Sensor Code: Causes and Solutions with Bank 2 Lean Codes

I've been troubleshooting a persistent issue on my 2004 Toyota Sienna. After replacing the original Bank 2 Sensor 1 with a Denso unit due to recurring lean codes (P0174) and P0051—later found to have no heater circuit continuity—the problem persisted. The Denso sensor continued to trigger P2197 and P0174, despite addressing vacuum leaks, replacing spark plugs, plenum, and throttle body gasket. The vehicle runs smoother now, but the O2 sensor fault code (P224-than 30 seconds after installing a genuine OEM oxygen sensor (part number 89467-48050), which is the superseded factory model for the original equipment. Immediately after installation, the car triggered P2242—'Oxygen Sensor Positive Current High'—within thirty seconds. This has led me to suspect a compatibility issue between the OEM sensor and the vehicle's ECU, even though Denso is officially listed as a Toyota-approved manufacturer. I'm now at a loss: Is this a known incompatibility? Or could there be an underlying wiring or signal issue with the new sensor? Any insights on diagnosing P2242 specifically on Bank 2 of a 2004 Sienna would be greatly appreciated.