I have a trouble code p0031 now i know what that is and where to start looking for it, but, last night I installed an adjustable sway bar, and when you do that your messing around with the charcoal canister. I expected a cell from maybe a loose hose or a related cell, but an O2 sensor malfunction?
Any constructive input is welcome

 

check the o2 sensor and wiring if you accidentally disconnected while installing the swaybar.

 

thanks for the response, this was a rear sway bar install, I've checked all my forums and my manual, and I can't find anything associated with the charcoal can and the o2 sensor Hopefully I'll have time today to go over everything

 

Now you get an obd2 monitor and it should tell you which one isn't working like bank 1 or bank 2, etc and the voltage it outputs. Usually the code tells you which bank its at. The voltage with a extremely slow response or no response is the culprit.

Bank meaning location. Input & output i suppose.

 

I do have a obd 2 code reader, but it's just a generic one, the only thing that it shows is the code p0031.My Cobb AP only gives me the code aswell. It doesn't tell me what bank or the voltages. If it comes down to it I'll hook up my volt meter and check the o2 sensor out.

 

I'm not sure what a 600 dollar access port does but if it doesn't log anything i would sell it.

At a minimum it should log values and provide trouble shooting codes

http://forums.openecu.org/viewtopic.php?f=4&t=3106

http://code.google.com/p/ecuexplorer/

 

Thanks for the links, I've been looking at the open source code programs. My AP is version 1 so it doesn't log anything. I think the second version does though.
Now all I need is a obd 2 to usb cord.
I'll have time tonight to look things over. I'm not too worried.

 

Does the car run any different than it did before the CEL? If it doesn't it's the rear sensor. The front sensor located on the manifold is the only wide band sensor used to control A/F ratio. The after cat sensor is a smog requirement for cat efficiency.

 

well you said charcoal canister so i am assuming a rear sway bar


and that is just coincidence...................... unless you did some crazy stuff on the install lol



P0031 - Front oxygen (A/F) sensor heater circuit low input


air fuel sensor is the front one

 

Well, I've checked everything out, all the hoses and electrical connectors are in place in the rear by the canister, I also cleared the code, unplugged the rear o2 sensor and started the car. Low and behold code p0031 pops up again.
Me thinks that the rear o2 sensor is bad. The car still runs fine, idles like normal, I can't take it for a drive because I'm at work until tomorrow morning.
It just seems strange that I did the rear sway bar and within 3 min of driving, the car throws a CEL.
It makes you second guess yourself
Thanks for all the input guys
If you can think of anything else that it could be please let me know

 

this thread i found might help you out http://www.clubwrx.net/forums/mainte...p0032-fix.html

 

Now I'm confused sigmi pi said "P0031 - Front oxygen (A/F) sensor heater circuit low input air fuel sensor is the front one"
and ipozestu said "Does the car run any different than it did before the CEL? If it doesn't it's the rear sensor. The front sensor located on the manifold is the only wide band sensor used to control A/F ratio. The after cat sensor is a smog requirement for cat efficiency. "

 

Awesome post crafty slug, I'll have to look at my front sensor and wires soon.
The cars 8 years old and has been running cobb stage two for 7 years, yeah it might be burnt out, or the wiring is shot.

 

i wouldn't go on the hunch on "if the car ran differently" There are tables in the ecu that can replace the functions of other things. Say for instance if the rear o2 sees a certain output and the front o2 sensor is dead, Then it'll try to adjust it self by using the rear o2's output.

This also occurs when coolant temperature sensor dies while you are driving it, it uses the pre-existing values and gets other information like from the map or maf sensor.

 

Well, I have to thank everyone who chimed in to help. Also To finish off a thread.
I replaced the front A/F sensor, and it's been 3 days of CEL free operations.
I'm going for a long drive this weekend so hoping all is good.

If you're doing the front A/F sensor get yourself a set of crows foot wrenches, you could probably pick up a set cheap at harbour freight.