MadGrip

just had my car diagnosed as having a faulty lambda, due to crap idleing etc..but where abouts in the exhaust system is it ??

the car is a MY01 WRX (bugeye) and I have a decat up pipe, decat downpipe, then theres a small section with a cat in, next is a fairly long centre section & finally the back box.

lame question I know , but where is the lambda situated ??

also, does anyone know a good place to get these from preferably in Leeds & is it a DIY job to change it


before you ask, yep I'm crap with cars

cheers

Phil

MarksWRX

Its in the uppipe. I've just had mine replaced, MY01, but they arn't available from Denso yet so £300 from Subaru, just for the sensor

MadGrip

Kin'ell £300 ??


anyone got one going spare that I dont need another mortgage for ??

are you sure its deffo the up pipe ? as I just spoke to Subaru and they said its £157+VAT and its in the downpipe

Bob Rawle

There are two, one in the collector of the headers at the bottom of the up pipe, thats a pseudo wideband and is the on eused for the closed loop off boost fuel adjustment and idle, the second is at the bottom of the downpipe or start of mid section and is a narrow band sensor, that is there just to check on the condition of the cat.

The front one is the expensive one unfortunately but thats the one you need and it does have to be the right one.

bob

MadGrip

Thanks for clearing that up Bob, it sounds about right as the idle is really lumpy but driving & boost is fine & I suppose in your knowledge you 'll know by the fault code

P0031 Heater control circuit (bank1 sensor1)

Can you recommend anyone to supply the part or is it a Subaru only part ?



not a happy Grippy

David_Wallis

good luck removing it

MadGrip

oh crap, its not the one I think it is !!!!!!!!

that'll never come out

David_Wallis

it is..

MadGrip

damn.. looks like I'm gonna need a new up pipe aswell

fancy another fitting job David

David_Wallis

not really

Far too busy at the moment..

personally I would grab it with molegrips after sticking some heat in and get what you can out.. then drill and retap or just run a tap to clean it up.. eitherway, up-pipe will probably need to come off.

David

MadGrip

was only joking about the fitting. I think the look on your face after spending 7 hours in my garage last time said it all

I'll give it a try when I get a bit more time. I'm a bit bogged down with work at the moment. Any consequences from using it at the moment or is it just the bad idle I'll have to put up with till I can get it sorted
Phil

David_Wallis

I wouldnt like to comment on that.. Ill let someone more experienced with the new age's comment..

David

Bob Rawle

It is "only" available from Subaru, it should come out though assuming its never been out, with a good close fitting ring spanner on it, not an open ender. As for running with it knackered it will screw the off boost considerably if its "off". The snsor will still be functioning as long as its hot enough though so the problem will be mainly in pootle mode or cold/semicold. These ecu's run stoich fueling right from start up (at least once coolant is over 20 degrees C).

As a check, just in case its a wiring fault, unplug the oxy sensor, if you look at the connector pins two are gold and two are silver, the gold ones are the signal and signal ground, the silver ones the heating cct, its pin 2 thats the positive heater supply and should have 12 volts on it wrt ground, check the car connector not the sensor connector. If volts are there then its the sensor. BTW you can confirm you have pin 2 as pin 1 should ring out to ground at less the 5 ohms. The resistance of the heater in the sensor ie across the two silver pins in the sensor connector should be less than 10 ohms, I suspect its not.

I think the sensor is in the headers not the up pipe and wait till its all stone cold to provide least resistance to turning otherwise it will probably rip the threads.

cheers

bob

MadGrip

Thanks for the detailed reply, I think its all a bit over my head though,so I'll have to find a good reliable local auto electrician
thanks again

Phil

MadGrip

after a bit more digging around the WWW I managed to find a semi-detailed pic of the Impreza exhaust system and it seems that the sensor in the up pipe is in fact the EGT probe (thank god for that eh DW ) Bob was correct in his assumption (not that I doubted him) that it appears to be the O2 sensor in the headers that is at fault.



Phil