O2 Sensor, Canada vs Non Canada What does this mean?

[jonfit04]

I am sure this is probably an easy question for some. How do you know when purchasing an O2 Sensor which to buy? I always see Canada or Non Canada...aswell as California Specs or Non California. I have 1999 Subaru OBS 2.2. I am getting ready to put it in the shop for a new front O2 sensor. I am going to buy the Bosch Universial Sensor( Good Idea?). I am doing this because I am having a shop install it and it saves me money and I wouldn't no the first thing about changing one. Any Advice would be great.

 

Thanks

Jonfit04

[OB99W]

Jon, the consensus here is that for the front O2 sensor, you should use an original factory (OEM) part; they seem to interface more reliably with the computer (ECU) and don't require splicing wires to connect. As previously suggested, providing the VIN of your car will help ensure that you receive the correct sensor -- in fact, most dealers (online and otherwise) won't fill your order without the VIN.

 

You might want to reread these threads:

http://www.ultimatesubaru.org/forum/showthread.php?t=64647

http://www.ultimatesubaru.org/forum/showthread.php?t=65371

http://www.ultimatesubaru.org/forum/showthread.php?t=66366

http://www.ultimatesubaru.org/forum/showthread.php?t=67209

http://www.ultimatesubaru.org/forum/showthread.php?t=67790

http://www.ultimatesubaru.org/forum/showthread.php?t=68086

[jonfit04]

Thanks for your help.... I went to the "Zone", got the exact codes that the CEL was giving. It gave a Knock Sensor Malfunction Bank 1 and then it gave me the

"P0136" Code for the Rear O2 Sensor. Should I change the rear 02 sensor first, since that is the code that was showing, or should I change the front O2 Sensor?

 

I thought I read somewhere that one reason for the computer giving the rear O2 sensor malfunction was because it was actually the front sensor causing the problem.....Is that a possibility?

 

Any input would be great.

 

Thanks

JMF

[OB99W]

Thanks for your help....

You're welcome.

 

 

I went to the "Zone", got the exact codes that the CEL was giving. It gave a Knock Sensor Malfunction Bank 1

Unfortunately, "Knock Sensor Malfunction Bank 1" isn't a code, it's the "meaning" of one, and doesn't seem complete. Perhaps the code was "P0325", which is "Knock Sensor Circuit Malfunction" ("Bank 1" isn't needed on engines with only a single bank). A circuit problem could be caused by a bad sensor, but also a wiring problem (corrosion in a connector, etc.), or even a problem with the ECU.

 

In rereading your previous threads, I know that you had tried replacing the knock sensor, and wound up with a worse-running engine. It could be that the replacement was overly sensitive (was it an original factory part?), but it's also possible that it was properly sensing knock (or something causing similar vibrations), and was functioning correctly.

 

 

and then it gave me the "P0136" Code for the Rear O2 Sensor. Should I change the rear 02 sensor first, since that is the code that was showing, or should I change the front O2 Sensor?

 

I thought I read somewhere that one reason for the computer giving the rear O2 sensor malfunction was because it was actually the front sensor causing the problem.....Is that a possibility?

A "P0136" code is pretty specific ("Rear oxygen sensor circuit malfunction") for that particular sensor, or a wiring connection to it. The confusion over front/rear O2 sensors being bad has to do with catalytic converter trouble codes, but you aren't reporting a catalyst-related code, so that isn't the issue here.

 

However, with the mileage you've previously reported on your car, and some of the symptoms, it wouldn't be a bad idea to replace both front and rear O2 sensors. (Poor connections should always be checked for when "circuit malfunction" codes come up, before replacing any parts.) Although the front sensor should be OEM, if cost is an issue you might be able to use an aftermarket unit for the rear one.

 

Sometimes, it just makes sense to have someone with good Subaru experience and proper test equipment (an OBD-II scan tool being used "real time", for example) take a look at things. Unfortunately, we can only do just so much when diagnosing problems by "remote control", Jon.

 

Best of luck in getting your Subaru repaired.