o2 Sensor CEL: New o2 Sensor did NOT fix.

[LarenF3D5]

Hey, I drive a 2002 WRB WRX. My car's throwing the CEL for the front o2 sensor. I got a replacement sensor from Advanced Auto and had it installed. The CEL keeps coming back on. I've got a couple questions and am looking for some advice.

I've heard there's a chance that the o2 sensor I got could be busted. What are the chances of that and should I look into that first?

I've also heard that o2 sensors from Advanced have a habit of not working well with WRXs, any input on that?

I've called the dealership and to get them to even look at the car it's $80, if it's simply an o2 sensor it's another $250 from there. That seems kinda ridiculous to me.

If the sensor itself isn't throwing the CEL (if the sensor's fine) what else could be tossing that code?


Thanks in advance, any advice would be appreciated.

[4cyturbowrx]

Try another brand of 02 sensor (bosh) If i am not mistaken there are a couple of sensor on your car What year Mods Miles.

[TrackReady]

Now what code is the vehicle throwing? 95% of 02 codes are NOT caused by a faulty o2. Is the code lack of switching? Slow switching? heater ck malfunction? Lean rich? If the code is for lack of switching, or switching below threshold then you probably have a vac leak that your ecu is trying to accomidate for by lowing IAC duty cycle and increasing fuel pulse width.

[LarenF3D5]

I drive a 2002 WRX with 82,500 miles, so it's a bugeye. My mod list is very small, and hardly a mod list at all.

K&N filter
Prosport Oil Pressure & Boost Gauges.

I've owned my car for a year and I've tried to keep it as close to OEM as I could for now. Its my first standard and I wanted to feel mods as/if I do them. (I've also been short on cash).

That being said the CEL was on before I did the filter and gauges. (It's been on for a while, but I was advised a front o2 sensor wouldn't make anything explode so I took my time with it).

I brought my car to an AAMCO to get checked out this afternoon. Apparently after resetting the CEL mine comes back on immediately. This led the AAMCO guy to believe it's a electrical short going to the sensor. (Supposedly) if it was an issue with the o2 sensor itself it would take 30-100 miles for the car to cycle and re-throw the CEL. And for mine it's immediate.

I don't know what the sensor code is exactly, but I've had it checked by 3 different shops now, and I've gotten back "Front o2 sensor failure" all 3 times.

I might take it to AAMCO tomorrow to try to get this potential "short" worked out, but I'm afraid of paying $75/hr for 2-3 hours of labor and the job not getting done.

[TrackReady]

They are partially correct, if the code was caused by somthing wrong w/ what the o2 was sensing the code wouldn't lite until a "drive cycle" was complete... On the other hand a circuit failure could be anywhere in the wiring or possible in the ECU, for them to assume it was the 02 wasen't the best idea. Checked for chaffed wiring, or even check the pins in the connector to make sure they aren't spred open or pushed back out of there locks.

[EJ257]

Did you send a message to Fred? Maybe we can get it worked out tonight

[lju]

I'm having what sounds to be the exact same problem on my 2003 bugeye wrx. I get a CEL and have a code reader, get the P0031 code. Immediately after I reset it, I get another CEL w/ the same code.

Haven't had a lot of time to diagnose it yet, was wondering if it turned out to be the wires or a connection and not have to replace the sensor?

-Jon

[slammed95gt]

I'm having what sounds to be the exact same problem on my 2003 bugeye wrx. I get a CEL and have a code reader, get the P0031 code. Immediately after I reset it, I get another CEL w/ the same code.

Haven't had a lot of time to diagnose it yet, was wondering if it turned out to be the wires or a connection and not have to replace the sensor?

-Jon

I am also having a problem with the p0031 code. I replaced it with a bosch 02 sensor that you splice in. I think the part number was 15730. It didnt fix it and the light came on immediately after it was reset. I was told that some replacements dont work as well as the factory sensor and may be the cause of the problem. I was skeptical but dont know what else to do.

[scaryc]

I'm having the same problem as you guys who bought the Bosch "splice yourself" o2 sensor. I installed it and cleared the code with my accessport and when I start the car it the CEL comes back on within 10 seconds. P0031.

Has anybody had success with this oxygen sensor from Bosch? Part # 15730

EDIT: Bosch sensor users, can you post up how you matched the wires together? I matched the two whites on the bosch to the two blacks on the OEM side(heater, no polarity), the black on the bosch to the blue on the OEM(signal), and the grey on the bosch to the white on the OEM(ground). I followed the table in the instructions and hoped it was right.

[slammed95gt]

I'm having the same problem as you guys who bought the Bosch "splice yourself" o2 sensor. I installed it and cleared the code with my accessport and when I start the car it the CEL comes back on within 10 seconds. P0031.

Has anybody had success with this oxygen sensor from Bosch? Part # 15730

EDIT: Bosch sensor users, can you post up how you matched the wires together? I matched the two whites on the bosch to the two blacks on the OEM side(heater, no polarity), the black on the bosch to the blue on the OEM(signal), and the grey on the bosch to the white on the OEM(ground). I followed the table in the instructions and hoped it was right.

Ya I wired it the same way...

[Donkey]

Trying to use the universal sensor to save some $$ is just not the answer.You can find the correct plug in replacement(Denso,NGK) online for cheaper than what the dealer wants.

[Cinnabuns]

I have the same issue. I've replaced the front O2 sensor with a 'factory' O2 sensor from Subaru. Next day I get the O2 code again on my AP.

I'm currently working on tracking this down but it is not due to the O2 sensor, it has to be something in the wiring.

I have a post named, "Same 6 CEL codes" if you want to watch any progress I make on this issue.
http://www.clubwrx.net/forums/genera...ing-wrong.html