Hi,

i think my O2 sensor ( Bank 1, Sensor 1 ) is faulty - Its the 4 wire sensor. JDM 2006 twinscroll. I found a few things online, but many for Foresters, about checking if there is a connection across the 2 black wires.

Ive tested with the multimeter can get nothing between the 2 black wires.

Can somebody please confirm if this is correct and i need to purchase one.

thanks

 

what voltage is it showing with ign on but car not running?
You need a obd connector and software to check what I asked.

 

Thanks for the reply Stig,

I have an ODB plugin reader, which flagged 2 faults.

P0031 HO2 Bank 1 Sen 1 Heater Circuit Low
P0134 O2 Sensor CKT No Activity ( Bank 1 Sensor 1 )

I'm not sure it does live checks.

Is there a way to test without.

thanks

 

Two white wires on the car side should have 12v when the ignition is on. Start there.

 

Thats not what voltage he should see from a live reading, done right anything above 1v tends to suggest sensor is old/poor, new sensors and working correctly sit under 1 volt, typically 0.8v.
Easy to check in say romraider.
hth

 

If you look at his error code it is heater circuit low. If you read what was said it says check on the car side if he has 5v or possibly 12v when the ignition is on. That is the heater circuit which will throw a code.
The two black wires which are the signal wires should fluctuate between 0.1 and 0.9.
It is quite possibly a fuse for the heater circuit Don will probably be able to assist on whether there is and where its whereabouts is.

 

Revisions F & G JDM STI / SpecC have a similar 5 plug ECU (STI - S2; SpecC - T1) to the MY05 UK/European STI

So assuming same/similar system wiring /ECU pin outs see attached pdf's.

I believe this is the correct part number

 

Thanks for the replies..

unless I’m being stupid, I can’t see a fuse in the diagrams.. just the relay.

I’ve pulled out every fuse under the dash and engine bay to check and all are fine.

I’ve checked for a connection between the two black wires on the sensor and it doesn’t read anything., I’ve read a few things online that say the two black wires should show a reading on the ohms meter. They don’t.

Don, you are correct, it’s that sensor, which is a pain as ICP are out of stock and wait time is 3 weeks..

thanks

 

So yours is the partial wideband sensor. I have one here that was removed from one of my cars when fitting a Syvecs ECU.
You first need to access the power supply to yours before purchasing another one
@Don Clark PDF should get you sorted in that department.

 

Order one from megazip, partsouq or amayama. You can pay for 3 day delivery if you're urgent.

 

The fuse is marked SBF-5 (Slow Blow Fuse) 30A, in the diagrams and located in the main fuse board in the engine bay, but is unlikely to be that as it covers multiple circuits (Main Relay, ECU, Fuel Pump Relay.......)

Japan
https://www.amayama.com/en/part/subaru/22641aa191

UK
https://www.torque-gt.co.uk/subaru-f...9-2002-on.html

 

Hello all,

Thanks for all the comments and advise.

Don, thanks for the PDFS.. really useful.

I tested the wires on car plug side and am getting the correct power.. So pretty sure its the sensor.

ordered, so hoping it will be here in a couple of weeks.

thanks again for all the help.