# Oxygen sensor



## Rix (Aug 14, 2004)

How do you know when to replace the O2 sensor?

I have a sentra with a GA15de engine..................


Isn't the O2 sensor found on the cat. converter on the exhaust manifold?


----------



## sr20jet (Feb 5, 2003)

Don't you mean GA16DE? You really don't need to replace your O2 sensor unless you get a check engine light. Then run the ecu codes for the check engine light status. If the codes tells you something O2 related, then it's time to replace your sensor.

There's 2 O2 sensors, front sensor on exhaust manifold and rear sensor on cat converter.


----------



## Ninety-Nine SE-L (May 5, 2002)

what part of the world are you in. There are some GA15s outside of the U.S., but I don't think the GA15 is a U.S. engine. Anyway, you need a special socket for the O2 sensors because of the wire, they make a socket with a groove in it that will allow you to easily get in there. There's one in the Exhaust manifold and one just past the Catalytic converter.


----------



## Token Moron (Mar 28, 2003)

sr20jet said:


> Don't you mean GA16DE? You really don't need to replace your O2 sensor unless you get a check engine light. .



there is such a thing as a ga15.. second...wrong, u dont have to wait till u get a CEL to replace the sensor.. sensors are part of the tune up process. replaceable every 60K miles(CEL or not)


----------



## lshadoff (Nov 26, 2002)

cHoPs said:


> there is such a thing as a ga15.. second...wrong, u dont have to wait till u get a CEL to replace the sensor.. sensors are part of the tune up process. replaceable every 60K miles(CEL or not)


Replacing the O2 sensor is not part of the Nissan recommended routine maintenance. 

If you feel there is a problem with an O2 sensor even though the ECU has not detected a fault, the Factory Service Manual has procedures to test the O2 sensor which are not very difficult. They require a high impedance multimeter. 

Lew


----------



## Token Moron (Mar 28, 2003)

lshadoff said:


> Replacing the O2 sensor is not part of the Nissan recommended routine maintenance.
> 
> If you feel there is a problem with an O2 sensor even though the ECU has not detected a fault, the Factory Service Manual has procedures to test the O2 sensor which are not very difficult. They require a high impedance multimeter.
> 
> Lew



true, however, oxygen sensors that are in bad shape do not always trigger a CEL and are known to kill performance/gas mileage...i figure them as just another preventative maintenance thing to check.


----------



## Ninety-Nine SE-L (May 5, 2002)

Hmmm, that's funny, I could've sworn the O2 sensor was on the 60,000mi maintenence schedule. I suggest replacing them around then to make sure you get good fuel economy.


----------



## nizzan4u2nv (Apr 14, 2004)

You dont always need a special 02 socket. I have pulled mine many times with just a wrench, both 02s i might add.


----------



## psuLemon (Apr 23, 2003)

^yea same here.. and then then unclip up the wire a little.. you dont need to replace your O2 sensor that often, places like midas and sears have stuff sayin how it is smart to replace then every 60k just to keep them clean and new and more money for the shops.

i have almost 100k on my car, without relocatin the sensor when i got the hotshot header, and i have checked the sensor it is still good, i still get like 30 mpg... but once you notice that your fuel economy is dropping, you might want to check them or if you throw codes


----------



## sentra305 (Jan 2, 2005)

but am confuse about one thing. My ecu says that the o2 sensor is open. Which brings me to think is it dead or just not getting electricity. Now another thing is that I dont knwo which one is bad the front or rear one. Either way am gonna change the Front one first.


----------



## lshadoff (Nov 26, 2002)

sentra305 said:


> but am confuse about one thing. My ecu says that the o2 sensor is open. Which brings me to think is it dead or just not getting electricity. Now another thing is that I dont knwo which one is bad the front or rear one. Either way am gonna change the Front one first.


There are different ECU codes for the front and rear O2 sensor. What car/engine/code do you have?

Lew


----------



## sentra305 (Jan 2, 2005)

lshadoff said:


> There are different ECU codes for the front and rear O2 sensor. What car/engine/code do you have?
> 
> Lew



I get a code 33 "oxygen sensor circuit open"

I have a nissan sentra manual 1995 gda16


----------



## Rix (Aug 14, 2004)

hahahahahaha............... YES IT"S A GA 15 de...............1498cc


I bought it straight from Japan as a used vehicle.................


----------



## lshadoff (Nov 26, 2002)

sentra305 said:


> I get a code 33 "oxygen sensor circuit open"
> 
> I have a nissan sentra manual 1995 gda16


That's the code for the front O2 sensor.

Lew


----------



## SoCalB14 (Dec 28, 2004)

one tip if I may.....Run the car to get the manifold nice and hot. Then try to remove it. If you don't do that, it will be MUCH harder to remove. Just be careful so you don't burn yourself on it once you remove it!


----------



## sentra305 (Jan 2, 2005)

bought a new boch oxygen sensor I did run the engine hot at first trust me it was much easier taking it off. Install the new one erase the ecu code and the check engine light has not come back ever since I have have use the car alot and ran it alot. So my problem hopefully is gone


----------



## Rix (Aug 14, 2004)

how much does an O2 sensor cost?


----------



## ifoam (Dec 16, 2004)

Rix said:


> how much does an O2 sensor cost?



they range from 25+


----------



## sentra305 (Jan 2, 2005)

a boch from discount auto part cost me 38 with tax 42 damn taxes


----------



## I'm Slow (Dec 30, 2004)

bought a bosch one from autozone for 16$ +tax all i had to do was take the old one off cut its wire crimp into new sensor and heat-shrink material around it took 15 min and saved me 25$


----------



## Ninety-Nine SE-L (May 5, 2002)

what is it, universal? What car is it for?


----------



## I'm Slow (Dec 30, 2004)

it was universial i bought it for my 96 200 se but it was in a bosch box and says bosch on it


----------



## FmrLCpl (Dec 29, 2004)

sentra305 said:


> a boch from discount auto part cost me 38 with tax 42 damn taxes


Where did you get the O2 sensor for $38? I checked serveral online stores and it costs like over $100 for the rear O2 sensor (1996 200SX SER, 2.0).


----------



## Token Moron (Mar 28, 2003)

FmrLCpl said:


> Where did you get the O2 sensor for $38? I checked serveral online stores and it costs like over $100 for the rear O2 sensor (1996 200SX SER, 2.0).


yea, our oxygen sensors are damn expensive(well, almost everything for the sr20 is)


----------

