hi my car failed its mot on a few stupid things which i have fixed but it failed on emmisions big time, problem is when i bought my car it was de-catted and had no lambda sensor or oxygen sensor fitted to the decat pipe. so i took the cat off my other scooby and fitted it to the car which had a lambda sensor at the bottom and oxygen sensor at the top, i plugged the lambda sensor in but couldn't find plug for the oxygen sensor?? i also noticed when i was under the car there is a oxygen sensor on the manifold under the engine on the driver side.

basically i need to find out where the oxygen sensor plugs into the car behind the turbo, and if anyone on here knows of any ways to reduce the emmissions. i did put in some petrol additives before mot and changed the oil and filter, anyone got any other ideas?

kinda need to solve this one over the weekend as if i return the car in 10 days i get mot half price. thanks guys

 

The wiring for the sensor just behind the turbo on the manifold comes out from the loom ontop of the gear box, I've had fun and games rewiring mine in this week!!

I've never had a problem with emissions when putting the cats back on (touch wood)

Not a sensible idea, but an induction kit will allow more air through and make the engine run lean

 

you don't mention age/model??

 

Mine, being a 95 car has the lambda in the up pipe,and a cat on fire sensor in the cat/down pipe,which isn't needed for the mot.

 

its a 95 wrx, basically all i have is the downpipe cat fitted which has two sensors fitted in it, lambda which i've got plugged in and oxygen sensor which i cant find anywhere to plug it in.

first things first i know these cars should have 2 cats but will it pass with just the one? senondly i noticed there is an oxygen sensor on the exhaust manifold so i replaced that with a new one. that should reduce the emissions right? also do i need to plug the sensor in the cat in too?

i'm not too clued up when it comes to scoobys

 

wat month 95 ???

 

if its pre sep i think 95 and a import you dont need any cats at all my friend

 

sorrys it should be pre august

 

no its a nov/dec so def needs a cat

just need to find a gaurenteed way to drop the emissions as i cant afford to keep getting it tested

 

http://www.vosa.gov.uk/vosacorp/repo...01992-2002.pdf


If your car is pre august 1995 and an import it will not need a CAT to pass the emisions test regardless of what your MOT station says, or anyone else. Print off the VOSA page and take it to the MOT station, they should then see the light. If they still argue ask to see the exact match in the analyser database, at which point they will either point out a UK impreza (which is wrong) or not be able to find them. The point here is that it must be an exact match and there is no entry for an impreza WRX or impreza sti. I did not know about this so bought myself a sports cat which was a needless expense. Had I known then what I do now it would have been a decat all the way.

 

could you not get/borrow a standard centre pipe of fleabay or sumwherewhere are you from???

 

Happened to me mate.

94 RA
It failed bad but they tweaked it some how
A couple of bulbs etc
Tweak

£250 Gutted!

 

what £250 just to get the emissions down?

 

Yes honestly..

they said they could plug it in and reduce it.

Only way i could pass it

Dodgy

 

i'd be cheaper buying the centre cat or bribing someone into just passing it lol

 

you dont need a cat is yours a import?

 

wat area you from

 

i'm from aberdeen north east of scotland

 

mine was pre cat

i got the print out n receipt

wot the ****

 

id go back erm wheres my 250quid u should of dun mot correctly he probably pocketed the cash then dun it correctly

 

 

Quick advice on mixed up terminology:

Lambda is a term used as the ratio measurement of the air to fuel ratio, a Lambda of 1 = perfect AFR. This measurement is done using a sensor that measures oxygen in the exhaust....Thus....

The Lambda sensor is an oxygen sensor...they are two words to describe the very same device. Your car (my95) only has one of these. This is after the turbo, but before the first cat. This is a crucial sensor, and has to be fitted and working correctly to pass an emissions test.

The second sensor is the cat on fire sensor. Not all imprezas have this fitted. But if it is, its fitted after the cat, its not needed for emissions.

 

just find a freindly mot station if you need one give me a pm its a bit of a travel though

 

If an import wrx or sti is not contained in the analyser database then it wouldn't matter if it's a pre august 1995 model or not surely. Mine is a jan 1996 model (just missed the facelift update grrrr ) wrx import so as it is an import mine probably wouldn't go through the cat test either based on chassis number model number etc etc...

Or do I ???

 

does this mean that any import impreza will only have one cat?

I have an STI 1997 V3 import.. How many cats would i have then?

 

ok sounds like you know what you talking about the sensor i have fitted before the cat is the one i cant find where it plugs into but i also have a oxygen sensor on the manifold under the car at the driver side which is plugged in. so what if i was to put the oxygen sensor from the manifold behind the turbo before the cat would that work? and reduce the emissions?

 

Only one minor downside to this and they will use it, if your car isnt an exact match to one of their records your ok, now the part you have not considered is that every car fitted with a cat since 1989 has to have a cat test, the fact is that it wasnt law until 1995 to have cats fitted to all vehicles, dont be confused with the idea that because it was before 1995 you can get away with removing the cat, by law its illegal.

Tony

 

The reason that you can't find the plug for the sensor before the cat is that it was never fitted there on a 95my car, the DP you have fitted is off a later car (97my on) which has its Lambda at the top (uk & import models) & the "cat on fire" sensor fitted at the bottom (import models only). as has been said, you can dissconect the "cat on fire" sensor if you wish, without any negative effects.

Your lambda sensor is fitted in the exhaust manifold, so forget the one in the DP, there is nowhere to plug it in so just leave it there unplugged.

If you are still having problems with the emissions (your car is quite capable of passing the cat test) then there is a problem with the way your car is running. You could have a knackered sensor, cat, or could have an air/exhaust leak.

Someone earlier said that their car was "plugged in" and had the emissions adjusted for 250 quid. this is not possible on these cars so don't fall for that one.

The emissions figures that the mot station give you can sometimes point you in the direction of the fault, so if she fails again then it would be good to post the figures up.

Phil

 

reasons for car failing are this,

EXHAUST EMISSIONS CARBON MONOXIDE CONTENT AT IDLE EXESSIVE

EXHAUST EMISSIONS LAMBDA READING AFTER 2ND FAST IDLE OUTSIDE SPECIFIED LIMITS.

FAST IDLE TEST FAIL
CO LEVEL =1.02% FAIL - 0.30
HC LEVEL =107PPM PASS - 200
LAMBDA =1.14 FAIL 0.97 1.03

SECOND FAST IDLE FAIL
CO LEVEL =1.00 FAIL - 0.30
HC LEVEL =115PPM PASS - 200
LAMBDA =1.14 FAIL 0.97 1.03

NATURAL IDLE TEST FAIL
CO LEVEL =1.01% FAIL - 0.50

OVERALL RESULT EXHAUST EMISSION TEST FAIL

NOTES:
ENGINE SPEED MEASUREMENT BY-PASSED
ENGINE OIL TEMP BY-PASSED - GAUGE WARM




thats what the emissions sheet says anyone help with that?

 

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