what differnt is oxygen sensors in front and rear position?

[Ryan Heo]

Hi.I want to replace O2 sensors both front and rear.I found a cheap place to buy only front sensors on ebay.However I couldn't find the rear sensor.What different is those things?Is the number of wires or totally different functions?If it is only wire, can I reconnect the new sensor with old connector if they has same numbers of wire?Thanks.

[maxhopper]

For one the rear sensor has a rubber grommet to seal the hole in the floor board where the sensor connects. http://www.sparkplugs.com has O2's for very reasonable prices.

[Ryan Heo]

You mean front & rear sensors are almost same. Only difference is the shape of terminal plug. If the front and rear sensor has the same number of wires, do I use the front sensor on rear position after replacing the new terminal to the old terminal plug which is from old plug?I mean the new plug is cut from wire and then rewired with old plug.Thanks.

[maxhopper]

Don't know for sure on them being the same part #. What you are talking about is a universal replacement. I've only used the OEM replacements that have the proper connector attached.

[Ryan Heo]

I found front sensor which is NTK brand on ebay.There is incrediblely cheap but they have only the front parts.So, I want to know whether I can use the front parts to rear parts or not.Thanks.

[ghettoslide]

The front sensor reads the o2 level before the catalytic converter. The rear sensor reads it after. The ecu balances it out with the readings from each sensor to determine if your cat is working corectly, and some read if you are running lean or rich. Replaceing with the wrong sensor will cause havoc with the ecu

[Ryan Heo]

I think better not to try...Thanks guys.