Rep Power: 196

So I had the check engine light come on and I checked the codes with my scanner and it came up with P0132 which by both the scanner and the service manual is Circuit high voltage on the primary O2 sensor. Now i cleared the Code just to see if it would come back but I have noticed that my gas mileage has gone down and it idles kinda rough at times. So far the light hasn't come back one yet.

Should I replace that sensor if it happens again AND, should I just replace both at the same time? I have about 140K miles or 230K kilometers on this 2000 civic (D16Y7).

Any help is appreciated

 
Rep Power: 811

yeah its rare for sensors to last more than 80k miles but it happens. they start getting slow response times as they age and the engine light may come and go. i would replace it now and get it over with. might as well do both, but the primary is the important one. stick with a honda sensor like NTK or denso.

 
Rep Power: 196

Yea i Have my eye on two Denso's right now. Thing is are both the sensors the same?

 
Rep Power: 811

no, they are both completely different. you cannot switch them around or bad things will happen. the primary is an active sensor partially responsible for how the engine runs by feeding readings back to the ecu, which then makes adjustments to fuel and air. it affects quite a few things like gas mileage and throttle response from a stop. the secondary sensor only has one function to tell the ecu that your cat converter is working. it does not affect how the car drives. if you switch them around, the check engine light will come on and you get hesitation when accelerating.

 
Rep Power: 196

Yea thats what i figured, I have been trying to figure out which one is for which. Currently I have this one ordered. Denso 234-4099 Oxygen Sensor (Air and Fuel Ratio Sensor). I believe the other one is 4096 ending numbers. I looked it up on their site. Front is primary correct?

 
Rep Power: 196

This is the link btw:
http://www.densoproducts.com/results...ctCategoryID=2

 
Rep Power: 811

yes the front/primary is closest to the engine, the secondary is usually further down the exhaust system, usually inside the cat converter.