I. Honda Civic Oxygen Sensor ReplacementRemove heat shield, spray old oxygen sensor with PB Blaster or Kroil (let it sit for a while), spray with PB Blaster or Kroil again, warm up car for several minutes, and use a 15-inch breaker bar on the end of a 22 mm oxygen sensor socket to remove sensor. Afterwards, clean threads thoroughly with brake cleaner, allow to sit for quite a while and “air out,” and install new oxygen sensor with anti-seize compound. Good cleaning technique is a must. Tighten to 33 lb-ft or 4.5 kg-m.I am not a fan of universal oxygen sensors or those made by Bosch for Civics. I recommend Denso sensors. Over time, you want the best sensor or you will pay for it in poor gas mileage and performance. Oxygen sensors are EXTREMELY sensitive to anything, particularly silicone spray, WD-40, or any oil on the pigtail connector. Don’t even use non-chlorinating brake cleaner or electrical contact cleaner on oxygen sensor connectors. NEVER use any of these products around the oxygen sensor or pigtail connector. If you do, the ECM will keep throwing a code forever, once the engine warms up and is out of “open loop” mode. Remove pigtail connector and gently dress the male and female connectors with jeweler files, if you suspect any contamination. FYI Pay close attention to the pigtail cleaning and to not use anything to clean them News source: Askme helpdesk