How do you replace an oxygen sensor?

First locate the sensor(s) - there may be multiple O2 sensors on a vehicle. O2 sensors are normally mounted on the exhaust manifold or in the exhaust pipe itself - usually one before and one after the cataletic convertor. A Haines or Chilton's manual (which will show the sensor location(s))for your vehicle should be available at any local auto supply store.

When you buy the oxygen sensor, you should also buy an oxygen sensor installation/removal socket (about $10-12) and a tube of anti-seize compound ($2.50). This 3/8" drive socket has a special cutout on the side to allow for the wiring connections.

Once the sensor(s) have been located and the replacement part(s) are in hand, warm up the engine and then shut it down. CAUTION! you will be working on a hot exhaust system - WEAR GLOVES - AND BE CAREFULL NOT TO BURN YOURSELF. The reason for warming up the engine is to get the sensor mounting area good and hot which will make it expand a little and thus make it easier to remove the sensor. You can probably do this with a cold engine but I assume it will make things a tad harder.

Remove the negative battery terminal, disconnect the wiring from the sensor(s) and then remove the sensor(s) using the previously mentioned socket. Spread a little anti-seize compound on the threads on the new sensor - being carefull not to gunk up the end of the sensor. Screw in the new sensor, re-connect the sensor wiring and the negative battery terminal. Bang - Zoom Your'e Done.

on 7th gen civc's (2001-2005) they are simply uncouple (five pole electrical clips) and unscrew with a crescent wrench (around a 23mm that i don't have) the screw in a new one and reconnect they are pretty much all the same on all vehicles they can be simple ones with a s little as two wires or as complex as eight or ten, but they are all prety much the sae for install and removal. unplug unscrew replace. Lonwel 2002 civic turbo @6psi