O2 sensor 2005 Subaru outback. Problem

mariyam1, Aug 26, 9:40am
Hi there can anyone help or advice please,, I have a 2005 Subaru outback check engine light staying on, scanned and got fault code po131 o2 sensor low voltage bank 1 sensor 1. Removed and replace sensor with aftermaket, light still staying on,, problem not solved. Getting fault code po132 cleared fault code. Road test and scan again got fault code po131 low voltage any ideas.

bigfatmat1, Aug 26, 10:00am
Ideally you need to check the sensor on a scope to make sure it is switching ok. Should switch about 8 times every 10 secs. If it is switching ok You need to look at why the voltage is low. Ie running lean. could be a vacuum leak anywhere after the a/f sensor. If not you will need to examine other sensors to make sure these are sending the correct readings. ideally this needs to be done in parallel with a scope instead of in series with a scan tool so you can see how the computer is responding to commands. But you may get a general idea by looking at the data stream on the scan tool. The quickest method is a scope with a exhaust or vac probe. Good luck! oh and dont forget to check connector for corrosion. wurth make a good spray for this comes in 4 seperate cans. connections at plugs are a big cause of faults.

intrade, Aug 26, 10:17am
well codes are not parts to replace how many 100 tousend times do i have to say that!
look at what fueltrim is doing LT and ST are
lt= long therm st= short therm. you need to look at them at idle and while driving . thats all you can do with a global obd2 tool. You should also read out codes with a oem scanner as there might be codes relating to why the other codes are set.
rest is on post 2 already dont know if anything makes sense but you need somone whom these 2 posts make sens to or you never fix the car correctly dont know how quick subaru advanced but on a 2005 nissan it could be a ton of other things causing that code to set.
bank 1 sensor 1 is the one befor the catalisator. bank 1 sensor 2 is after cat

aredwood, Aug 26, 11:31am
Or it could be a missfire. Oxygen goes down exhaust. Sensor detects oxygen. ECU tries to adjust amount of fuel injected. But that oxygen will never go away due to missfire. So ECU assumes sensor is stuffed

clark20, Aug 26, 7:28pm
"Removed and replace sensor with aftermarket"

This could be your problem, no guarantee it will be compatible. my Honda would not accept an aftermarket one.

bigfatmat1, Aug 26, 7:56pm
Yes especially when you mix up the type in there i.e zirconia & titania.

bigfatmat1, Aug 26, 8:00pm
I believe this would not cause a 02 voltage low code. As low is lean. Miss fire is more likely to cause a cat ineffeciancy code. For No2 sensor. The voltage needs to remain low for a predetermined amount of time generally quite a while before we see a low voltage code I think we could safely rule a miss fire out.

321mat, Aug 26, 11:51pm
There are two Oxygen sensors on your engine.
Which one did you change?

From memory, I think the front one controls the idle, while the rear looks after the running duties once the car is above idle.

You may have a fault with the other sensor.

mariyam1, Aug 28, 9:36am
Hi there, I would like to thank you all for your help. Problem solved genuine sensor fitted. Problem solved.

Cheers

intrade, Aug 28, 9:43am
Did you look at fueltrims because onlythen do you know if its solfed

lugee, Aug 28, 3:06pm
Thousand.

THOUSAND.

It just really bugs me.

strobo, Aug 28, 6:10pm
Good job ;-) Don't forget to fit a new air cleaner & check for Intake induction leaks too , re-tighten & check all clamps.

strobo, Aug 28, 6:30pm
AEIOU & Please! please,Please try and set a good example by stressing the syllables ;-) Cheers

llortmt, Aug 23, 10:10am
How many other languages can you post advice in?