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Denso 02-04 RSX / 02-05 Civic Si Primary O2 Sensor

Denso 02-04 RSX / 02-05 Civic Si Primary O2 Sensor-A1
Denso 02-04 RSX / 02-05 Civic Si Primary O2 Sensor-A2
Images may be for reference only

Denso 02-04 RSX / 02-05 Civic Si Primary O2 Sensor

★★★★★ ★★★★★ 62 Reviews

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9 In Stock


This Denso O2 sensor is the wideband air/fuel sensor that you need for your 02-04 Acura RSX (DC5), 02-05 Civic Si (EP3), and 02-04 Honda CRV. This is also the primary 02 sensor needed for Hondata KPro for the 05-06 Acura RSX.

Don't be fooled by the much lower prices from other websites that tell you their sensors come in a Denso box but may have been manufactured by someone other than Denso - that simply means you are not purchasing an authentic Denso sensor and are overpaying for a Denso box. K Series Parts only sells real Denso sensors in Denso packaging.

This sensor is a direct replacement for the Honda/Acura parts: 36531-PRB-A01.

This Denso oxygen sensor is direct plug and play so no cutting or wiring is required for installation.

Denso Description

DENSO's light duty oxygen sensor started to appear on vehicles with the development of fuel injection systems. The basic job of the sensor is to monitor the air fuel mixture under idle, moderate acceleration and cruise conditions. Under heavy acceleration the oxygen sensor goes into "open loop," which basically means that the engine management computer system ignores the oxygen sensor. Oxygen sensors have a smaller range of limits in detecting and adjusting the difference from an optimum air/fuel ratio.

As the automotive industry continues to improve on their standards DENSO is keeping the pace with advancements in our engineering to meet the demands from the industry. Also, as car owners are holding on to their vehicles for longer periods, DENSO continues to make auto parts available for those critical replacement parts for all applications.

Oxygen Sensors

Oxygen sensors, also known as Lambda sensors or O2 sensors among some vehicle manufacturers, are among the most sensitive and critical components on your car's engine. Earlier fuel injection systems employed one oxygen sensor in the exhaust system to maintain closed-loop air/fuel mixture control. However, today's engines may use as many as four sensors, which monitor not only exhaust gas oxygen content but catalytic converter efficiency as well. In order to perform these functions properly, the sensors must adhere to OE standards within incredibly close tolerances. A malfunctioning or incorrectly calibrated oxygen sensor can hurt driveability and illuminate the malfunction indicator, resulting in costly and time-consuming repairs. DENSO First Time Fit® oxygen sensors are designed to meet those tolerances and more. The DENSO oxygen sensor catalog offers one of the most complete product lines in the industry, from Acura to Volvo.


  • Corrosion-resistant stainless steel construction
  • PTFE filter blocks efficiency-robbing contaminants
  • Refined zirconia element improves sensor response


  • Superior design maximizes engine performance and fuel efficiency while reducing fuel consumption and harmful emissions
  • First Time Fit® delivers the right part the first time
  • Ensures smog test compliance


Brand: Denso
Part Number: 234-9005
O2 Sensor: Primary
UPC: 42511110403

Vehicle Fitment

Acura RSX
2002 Acura RSX Automatic 2003 Acura RSX Automatic 2004 Acura RSX Automatic
2002 Acura RSX Manual 2003 Acura RSX Manual 2004 Acura RSX Manual
2002 Acura RSX Type-S 2003 Acura RSX Type-S 2004 Acura RSX Type-S
Honda Civic
2002 Honda Civic Si Hatchback 2003 Honda Civic Si Hatchback 2004 Honda Civic Si Hatchback 2005 Honda Civic Si Hatchback
Honda CR-V
2002 Honda CR-V All 2003 Honda CR-V All 2004 Honda CR-V All

62 Reviews ★★★★★ ★★★★★

★★★★★ ★★★★★
4.97/5.00 Stars out of 62 Reviews
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5 Most Recent Read All 62 Reviews
good for its price
Sheldon Fernandez | December 9th, 2015
Cleared my CEL so far,as it should. Great product thus far
cleared P1166-P1167 code
aferdiansyah | February 9th, 2015
As described and great fitment. Replace with this product and no more code and engine running smooth with much better gas mileage. Worth the price. Thank you!
Good by CEL
valter pedreira | November 13th, 2014
Installed on a 2002 rsx type s,fitment was great,quick shipping great price.Saved big $$$$ compared to dealer price
what u pay for , is what u get !
Algenis Gandarilla | September 18th, 2014
Installed on my 2004 civic si ep3 after diagnosting it had a bad 02 sensor, CEL came off right after install. Car feels a lot more smoother at idle , gas mileage got a bit better, definitely worth the $$, Kseriesparts has the best deals and I will definitely continue to buy from them
Took care of my CEL
David Moller | July 4th, 2014
CEL light would turn on. And my rpm would go too low when car @ stop. Just a littl push of gas and it would stall. It would go away when i open the fuel cap. But withing few days it would come back on. Eventually after a few months. It just stayed on. After getting a free read @ local autoparts & from reading @ few forums. Idecided to replace this sensor. Its pretty easy just raise the car from passenger side high enough.Took off the side skirt to make it a little easier. Having the O2 sensor rem. socket also helps but not necessary. Car runs great now. Super fast shipping!
Read All 62 Reviews