Hi
I am needing some help with my Impreza, It is a 1994 Classic Impreza WRX turbo
It is running standard ECU, Has a Apexi Filter on it, and a Blitz Nur Spec Exhaust with a high flow cat on it in the down pipe,
There is only a lamdba sensor in the headers. and not one after the turbo in the downpipe, the wiring is there but no sensor.
I have had it on the emissions today and the Lamdba is all over the place and the CO is running 10.2%... The limit is 0.3%

Do you think this is due to it not running a rear Lambda?

Thanks for you help
Cheers
Baz

 

yeh, sometimes a faulty/old lambda is the reason of a mot failure, however i also heard that you have to get the sports cat really hot to pass mot also

 

The cat was really hot, I took it for a run before I put it on the tester.

 

the sensor wiring in the down pipe will be the cat on fire sensor wiring. forget about that. not needed. suggest performance cat is duff or bad lambda sensor.
even with my standard downpipe it took a few attempts to get it through the mot (had to wait for cat to heat up).

 

10.2 is way high fella id suggest abit more than just lamba

 

Any other suggestions then?
Exhaust is brand new and so is the high flow cat.
Cheers

 

what was the hc reading mate?

 

i have a few lambda sensors AA410 and AA850
(i am an ex prodrive employee)

 

HC reading was all over place too, One min it is in the limit but then when emissions and Lambda reading go high so does the HC's.... Lost what to do at the moment.

 

what does the car run like is hesitant or anything or drive fine mate?

 

When I first start it up on a morning it wont idle properly for about 5mins, then its fine. it drives spot on, Cant fault it at all when driving, this is my 2nd one and this one is less economical than the first one I had,

 

well id say 1 of 3 things mate either water temp sender,air flow meter or lamba but with out taking some readings of her its hard to give 100% mate

 

Cheers mate, I wondered about the temp sender, Is that under the inlet manifold?

I've got a spare front Lambda so may swap that over this week. Ihavent got one in the downpipe as yet though, finding it hard to find one that has two wires to match my car.
I have tried a different air flow meter so know its not that.
Cheers for your help
Baz

 

yeah the temp sender is under the mani on the cross over pipe mate,try the lamba and go from there first but if the ecu is getting the wrong reading from the temp unit then it would fuel all over the shop
hope this helps mate.

 

Thanks for your time, I'll try the lambda on monday night and then let you know how I get on. Thanks again
baz

 

no worries baz let me know
Prodriverules

 

For what it will cost you, fit a new Lambda sensor in the headers at the collector nearest the driver's side wheel. That was the only Lambda sensor fitted to your model. Get it nice and hot and see if it will pass the MOT and remind the tester of your model year. Now if it still fails I suggest you need to find someone local to you that knows about Subaru WRX of that age and take it from there.

 

Update on my WRX Impreza...
I have tonight swapped the Lambda sensor over in the Header with another one. It makes no difference at all the emissions. On idle the emissions are about 0.6CO and about 1.1 on Lambda, as soon as you bring the revs to 2500RPM the CO goes to 10.2 and the Lambda drops down to about 0.5 which is too low... Does anyone have any other thoughts.

Also I have now noticed on the ECu it has a Mines ECU on it.... Could this be my problems??

Cheers
Baz