cube320

Hello i have a 2002 wrx and i have this error code:

p-0031 H02s heater control circuit low (Bank 1 sensor 1) I have tries 2 sensors now and the code wont go clear.

The sensor i have replaced twice is the one by the down pipe ( you can see it sticking out when you look from above on the drivers side with the bonnet open) the 4 wire one. Is this the correct one i should be looking at.

As i have brought 2 sensors now and just paid £100 for a used one and that still has not cleard the code im starting to think it may be somthing else.

Can any one help

Thanks

Butty

iTrader: (2)

A 2002 car has the main O2 sensor in the exhaust manifold and has to be replaced from under the wheel arch, so I don't know what sensor you have been dealing with?

I'd look at resistance of the supply and earth wires for the sensor heater to see if there is a break.

Got a picture?

Nick

Midlife......

iTrader: (2)

Have you been changing the EGT sensor (which the bugeye WRX has and the STi doesn't) ??

Shaun

cube320

Ill post some pictures in a minute to show you

Thanks

cube320

Is this the right sensor?

Thanks

Midlife......

iTrader: (2)

P0031 CEL is the Front oxygen (A/F) sensor which is accessed by way of the the offside wheel arch and AFAIK cannot be reached from under the bonnet (which is what butty says). The Rear 02 sensor is in the downpipe and again AFAIK it can't be reached from under the bonnet.

The only thing I can think of is that you have been changing the EGT sensor which is in the short up-pipe of the bugeye WRX.just downwind of the pre-cat....

http://www.wallpaperinstaller.com/scooby/mattspec.gif

Shaun

cube320

From looking at the diagram i have been replacing the right one. The one on the drivers side. Behind the wheel arch liner.

Can two of them be faulty becuase i have ordered them from a breaker reccomended from here?

Butty

iTrader: (2)

So there's no O2 sensor in the exhaust manifold anymore and you've relocated it to the downpipe.
The main loom wiring looks hacked up - what happened there?
I'd check the quality of those spade connector joins and if they are wired correctly.

Did the sensor failure start after that wiring work was done?

Nick

Midlife......

iTrader: (2)

See post 6 here......is this the sensor you've been changing

http://www.scoobymods.com/best-damn-...ipe-t6649.html

Shaun

cube320

Yes from looking at that topic above, yes that is the sensor i have been replacing.(post six). Is that the correct one?

The wiring was like that when i got the car a year ago.

Thanks for the replies

Midlife......

iTrader: (2)

Well you are deffo changing the front 02 sensor My guess would be faulty wiring or connector as it's unlikely two sensors are faulty.

What do you reckon butty ?

Shaun

Butty

iTrader: (2)

That dodgy wiring needs looking at. I presume it was cut to add some sort of signal modifier by the last owner?

Midlife......

iTrader: (2)

Cube 320

Have a quick look at the rear o2 sensor (see diagram)...does it look intact or is there a black box somewhere spliced into the wire. I just wonder of someone has fitted a de-cat and messed with the wiring to fit a scoobysport type "electronic CEL fix" and fiddled with the wiring.

Just a thought


Shaun