BDFHYK Oxygen Sensor Upstream O2 Sensor, Compatible with Honda Civic L4 1.7L 2005 2004 2003 2002 2001, only for 36531PMSA01, 234-4123 Replacement 1PCS

This BDFHYK 234-4123 upstream O2 sensor is an OE-style aftermarket replacement for listed 2001-2005 Honda Civic 1.7L L4 applications and cross-references 36531PMSA01. Before ordering, confirm the 1.7L engine, upstream exhaust location, original sensor number, connector, wiring, lead length and emissions configuration. Similar Civic model years can use different sensors by engine or position, so compare the removed sensor before installation. A stored diagnostic code alone does not confirm sensor failure.

234-4123 Upstream O2 Sensor Fitment for 2001-2005 Honda Civic

234-4123 O2 Sensor Interchange References

Replacement references include 234-4123 and 36531PMSA01. Match the reference together with the connector and upstream location.

234-4123 Upstream Sensor Position Check

This SKU is listed for upstream use. Do not assign a universal Bank 1 Sensor 1 or Bank 2 Sensor 1 label without service information for the exact vehicle and engine.

234-4123 O2 Sensor Diagnosis Before Replacement

Inspect the connector, wiring, heater circuit, related fuse, power and ground, exhaust leaks, intake or vacuum leaks, fuel pressure, injector operation and misfires before replacement. Fuel-trim codes require diagnosis before parts are changed.

234-4123 O2 Sensor Installation Notes

• Allow the exhaust system to cool before service.
• Use an O2 sensor socket or suitable wrench.
• Compare the connector, lead length and original reference with the removed sensor.
• Inspect bung threads and start the sensor by hand.
• Use anti-seize only when permitted by the sensor instructions.
• Tighten to the applicable vehicle service specification and route the harness safely.

234-4123 O2 Sensor Package Contents

• 1 × BDFHYK oxygen sensor

Important: This is an OE-style aftermarket replacement, not a factory-branded part.