nct emission failure

R

rinty

Sunday Drivers
failed the ol NCT on emissions tonight
ej25 sti engine in classic impreza mapped on apexi power fc.


test 1. (no diptaine)

low idle CO 5.36 vol% (above 0.5% = fail)
HC 301ppm (above 0 = fail)
high idle lamda 0.87 (not between 0.97 and 1.03 = fail)
CO 4.74 vol% (above0.30% = fail)
HC 140ppm (above 200 = fail)

test 2 (diptaine and a spirited drive before hand)

low idle CO 3.96 vol% (above 0.5% = fail)
HC 186ppm (above 0 = fail)
high idle lamda 0.91 (not between 0.97 and 1.03 = fail)
CO 3.71 vol% (above0.30% = fail)
HC 129ppm (above 200 = fail)

any ideas??

any good specialest place near galway to get it within the pass threshold.

other than leaving €50 stuck in the steering wheel and try to bribe the lad when i sent it in again.
 
Is there a cat in the car or do you have decat system.

If decat there is your problem I would say.
 
complete standard exhaust on the car.

sorry probably should have mentioned that above
 
its running far too rich, (so either getting to much fuel or not enough air) id be checking for air leaks around intake manifold possibly a vacuum pipe leaking etc. but if its using oil more than likely thats your problem
 
yeah the oil usage is definatly a concern.

theres no leaks in the exhaust and havnt had problems with lamda

if i weld in an extra cat will that fix it for the test.

like the standard pipe is comming off as soon as it passes.
 
Could be a mapping issue at idle too rich either . Catted down pipe off the turbo fitted?
 
yeah it has the cated down pipe.

it passed the test in july 2013 with this map with everything well inside the limmits.

the standard pipe has only been on the car for about 600km.
 
thanks lads

I checked the lambda on the ecu commander and it reading 2.7v when idling and up around 4v when driving.

from what Ive read the lambda should put out less than a volt so I guess the lambda sensor is goosed.

next question is where is the best place to get a new one.
 
Your lambda output should be oscillating from somewhere around 0.1 to 0.9v with a midpoint of 0.45v if it is a 3 or 4 wire sensor.
Rear should read circa 0.45 constant if mixture is correct.

If it is 5 wire broadband I think outputs can be up to 5v depending on car not sure off top of my head.
What is in yours.

first off determine your sensor type, then determine what correct output should be.
introduce a lean mixture by pulling off vacuum pipe, the readings should go one way. spray carb cleaner around that vacuum pipe or intake to introduce rich mixture and the readings should go the other way.
if sensor doesn't respond its f*cked, if it does look elsewhere.
 
sound for the advice lads

it was the lambda sensor(3 wire).

replaced it today and had a garage do the emissions test and it was well within the limits.

nct retest on wednesday night. hopefully there will be no problems
 
You must log in or register to reply here.
Back
Top