Question about 2005 Subaru Outback

1 Answer

I pulled the CEL code P0031 from my 05 Outback. Changed the front O2 sensor and reconnected everything. Cleared the code with the OBD2 reader. Upon startup CEL put out another P0031. Does the computer need to reset over a few days? Car is totally stock no exhaust mods and only 28500mi. Any advice?

Posted by on

  • CarpeD Dec 11, 2009

    Is there a voltage or impedance that can be measured at the O2 sensor connection to the harness? I would like to track only 1 wire instead of all 4. Any suggestions where to start would be great.




1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Top Expert:

    An expert who has finished #1 on the weekly Top 10 Fixya Experts Leaderboard.


    An expert that got 20 achievements.


    An expert that got 10 achievements.

  • Subaru Master
  • 83,772 Answers

This is a hard fault, this means u have a wiring problem, the sensor was good, that is why the PCM set a code for the same fault right away.

Posted on Dec 11, 2009

Testimonial: "Thanks for the quick info."

  • Marvin
    Marvin Dec 11, 2009

    yes u check the voltage which should be constantly varying between about .25 and .55 volts, u need a scanner with live data capability to do these tests, u can buy these on Ebay for around $80



1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

2002 Subaru Forester P0136 see P2270 P2271 intermittent idling fluctuation and acceleration hesitation

Is the wiring good going to the O2 sensors? Maybe just look the car over and see if you have any bad grounds. They can do weird things. Could be a bad ICU.

Jan 22, 2012 | 2002 Subaru Forester

1 Answer

2000 outback check engine light on all the time, changed front o2 sensor, changed fuel cap, unplugged battery, and none turn this light off.\r\n any suggestion?

You have to hook an OBD 2 scan tool up to the data link connector and check to see what code is present. If you have a knock sensor code, you need to replace the knock sensor. If you get a P0420: Catalyst system efficiency below threshold, you will need to replace your catalytic converter. But if it is nothing important, the only way to clear a check engine light is with a scan tool. You can usually go to any aftermarket parts store and they will check and clear you codes and light for free. I hope this info helps.

Jul 27, 2011 | 2000 Subaru Outback

1 Answer

Just changed o2 sensor. what do i have to do to get the check engine off?

The codes will have to be cleared with a scan tool or some code readers can also clear codes.

Apr 17, 2011 | 1999 Chevrolet Malibu

2 Answers

My 97 ford f150 is loafing an when i put on a diagnostics test its reading out 02 sensors an i change all four and i also change the massive airflow sensor, and i also had the fuel system cleaned and its...

If it's still reading 02 sensors and you replaced them AND assuming you cleared codes I suspect bad cat, converters, The 02 sensors when everything is operating properly, the front 02 sensors read different from rear ones - if they read the same, you get code/light. Plus with your description sounds like bad converter(s)

Mar 23, 2011 | 1997 Ford F150 Regular Cab

1 Answer

Check engine light on, cruise light blinks on dash

I am in the middle of diagnosing the same problem, : It means there is a malfunction in the exhaust gas system. Possible to have bad gas,(water in fuel, or old gas) or in winter "winter fuel" additives can send the O2 sensors out of whack. There is a front and rear sensor on the 2007. The front is 200 bucks msrp and the rear is 145 bucks msrp. You could pull the battery cables off then reattach 20 mn later but the code will return within a while due to never clearing, therfore eventually you will need to take the car to the dealer to have the code cleared. Or do it with a OBD2 Code reader yourself. The reason the cruise is disengaged is to prevent the car maintaining a constant rpm for long periods.(protection mode) All in all your Subaru dealer could cancel the code. but if it returns it could mean a 800 dollar O2 sensor repair bill.

Dec 12, 2010 | 2007 Subaru Impreza Outback Sport Wagon

1 Answer

2000 Subaru legacy outback 2.5L DTC P0420 code will not clear. I replaced the rear O2 sensor and the CEL is still on. I used the scan tool to clear the code but it will not clear.

that code is saying you have a problem with that system. if you go to autozone thay can print that code out for that tells you what to check. other then that you may need to get it diagnosed by a professional

Nov 22, 2009 | 2000 Subaru Outback

1 Answer

How do i know if i need to replace the oxygen sensor?

on your vehicle the obd1 computer is not as sensitive as obd2 .i have seen o2 sensor not working and no codes were set. so if the sensor looks rusty on the out side or you know that the sensor has not been changed in several years i would replace the o2 sensor.remove the battery ground cable for a couple of minutes to clear the learned values,replaced the o2 sensor then reconnect the ground cable start engine let idle for 2 minutes in park,then 1 min. in drive,then drive for approx.10 min. this will help the computer to relearn.hope this helped

Oct 30, 2009 | 1994 Chevrolet S-10

Not finding what you are looking for?
2005 Subaru Outback Logo

972 people viewed this question

Ask a Question

Usually answered in minutes!

Top Subaru Experts


Level 3 Expert

83772 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22413 Answers

Brandon Johnson
Brandon Johnson

Level 2 Expert

251 Answers

Are you a Subaru Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides