I have an 01 Forester that I just put a new upstream O2 sensor in around April because the code said it was bad. Now the check engine light is on agian saying the same sensor is bad again. Is there any other thing in the system that could be causing them to fail early? Thanks

many fuel system cleaners, sprayed directly into the air intake can cause failure - also, silicone sprayed anywhere near the air intake can also fry an O2 sensor

 

most O2 sensors are warranteed - could be a bad one and no sense paying another $80 for another new one.

 

Also, other component failures could trigger this particular O2 sensor error code thats triggering the CEL - only way to know for sure is to read the voltage signal coming off the O2 sensor and see if it is actually varying with different fuel/air conditions - many scan tools will allow you to read the data in a real-time mode.

 

hope this helps. good luck

What code are you getting, and is it the same code as before?

I have an 01 Forester that I just put a new upstream O2 sensor in around April because the code said it was bad. Now the check engine light is on agian saying the same sensor is bad again. Is there any other thing in the system that could be causing them to fail early? Thanks

 

was it a subaru sensor or aftermarket.?

was it a subaru sensor or aftermarket.?

 

What he said. The front one really needs to be a subaru sensor. Pay a bit more, but fix it once and be done with it. Otherwise look for an exhaust leak. Also you may have to take a multimeter to it to get a better idea whats going on if it is an OE.

 

 

nipper

What code are you getting, and is it the same code as before?

 

 

Same code and I used an after market sensor.

 

I'll try it again with one from Subaru.

 

Thanks for the help.

Same code and I used an after market sensor.

 

I'll try it again with one from Subaru.

 

Thanks for the help.

There are many O2 sensor codes that can mean many different things could be wrong, many that have nothing to do with the O2 sensors themselves. Getting a Subaru sensor is a good idea, but it may not solve the problem. If/when the code sets again please give us the code number so we can give you a better idea where to look next.

Slightly OT, but... Are the Subaru sensors made by somebody other than ND? Even the "Bosch" brands around here are just repackaged NDs.

Slightly OT, but... Are the Subaru sensors made by somebody other than ND? Even the "Bosch" brands around here are just repackaged NDs.

 

the subaru oem that i've seen said denso i think. is that the same as ND?

the subaru oem that i've seen said denso i think. is that the same as ND?

 

Nippendenso.

 

Here is why aftermarket is not as good (I worked for an Autopart mfg at one point in my life). You have the parts that are supplied to OE, which have to fit very specific criteria on performance. OE sighns a contrac stating that they will meet that spec for as long as they sepcify that spec. That is a guarentted sale of X# of units to subaru.

 

Out the front door, those units are not yet sold to anyone. So to svae costs they go through their catalog and prints to see what a given part has in common to other parts that are similar to it. When they find something that is fairlt close, they will combine it with others and make it a one size fit all (this was my job) to save cost. The parimeters can be response time, heat up time, range of response, looks, wire length, etc etc.

 

The only people that know where they differ are the engineers that did the consolidation, or people on boards like this that can be a giant test lab.

 

nipper

 

PS i am surprised that bosh and ND are the same

Nippendenso.

 

Here is why aftermarket is not as good (I worked for an Autopart mfg at one point in my life). You have the parts that are supplied to OE, which have to fit very specific criteria on performance. OE sighns a contrac stating that they will meet that spec for as long as they sepcify that spec. That is a guarentted sale of X# of units to subaru.

 

Out the front door, those units are not yet sold to anyone. So to svae costs they go through their catalog and prints to see what a given part has in common to other parts that are similar to it. When they find something that is fairlt close, they will combine it with others and make it a one size fit all (this was my job) to save cost. The parimeters can be response time, heat up time, range of response, looks, wire length, etc etc.

The only people that know where they differ are the engineers that did the consolidation, or people on boards like this that can be a giant test lab.

 

nipper

 

PS i am surprised that bosh and ND are the same

 

 

i love it when you talk smart.......

i love it when you talk smart.......

 

 

awwwww

 

*blush*

 

see i really am good for something