Oxygen (O2) Sensor for Civic 1.8L — Upstream and Downstream Replacement
A replacement heated oxygen sensor for the 1.8L Civic, available in upstream (pre-catalyst) and downstream (post-catalyst) positions. Cross-references 234-9124, 234-4350, 36531-RNA-A01 and 36532-RNA-A01.
Key Features
Upstream and downstream options
Direct-fit connector on the listed part numbers
Heated sensor
Before you order
Choose upstream or downstream carefully — they are not interchangeable and check your car's exact year and engine against the part numbers above. Compare the connector and cable length to the sensor you are removing.
A fault code pointing at an oxygen sensor does not always mean the sensor is bad. Exhaust leaks, a failing catalytic converter and wiring faults set the same codes. Diagnose before replacing.
Trademark notice
This is an aftermarket replacement part. The OE numbers are listed only to identify fitment.
This is an emissions-related component. It must be a functioning sensor fitted in its correct position — do not use spacers, defeat devices or non-functioning substitutes, which are illegal for road vehicles in most countries.
