Can anybody give me any help or advice on how i can get the emissions down on my STI5. The car failed the emissions test yesterday,the car was hot when tested but i did notice the exhaust was still quite sooted eaven after a 10 mile blast to the SVA test centre, the car has a standard air box and a standard sti exhaust, any help would be greatley appreciated.

[Edited by fixit - 2/27/2003 10:39:21 PM]

 

What was the lambda value when tested - if not very very close to 1 it is usually the lambda sensor.

Tell us the CO, HC, lambda.

 

could possibly suggest a fault with an 02 sensor, as if engine fuelling incorrect,would give wrong readings on emission test.

 

The first fast idle test the CO was 2.22 the HC was 77 and the lambda was 0.94 The second fast idle test the CO was 2.18 the HC was 78 and the lambda was .94 and also on the natural idle test the CO was 7.26, will giving it on oil change alter the readings do you think ?

 

before they completly closed the loophole we tested a few import scoobies when they were brought in and they usually struggled with the test but not by that amount at idle, may well be worth a lambda sensor change or if you can be botheed tap into the loom to it and measure its readings, i'm sure someone can tell you the correct figures ( i should know but it's been a few years since i studied this sort of thing)

we actually found that they would usually come into the pass range if they were run for a decent length of time (2 - 300 miles) on uk petrol but it was always marginal

 

Thanks for that tinvek.

 

Very likely your lambda sensor based on those results - it is running rich which they tend to do by default if running open loop with no intake mods.

 

Am i right in thinking that it is not a fault of the maf air sensor as that makes them run lean?

[Edited by fixit - 2/27/2003 10:44:20 PM]

 

On re-mapable ECU's is it possible to have a map specifically to get around emissions testing (make it run lean) - MOT's and the dreaded on the spot from PC plod !!

 

lots of vauxhalls have this "tweak" as standard which is one of the ways that superchips etc made them feel faster. it used to be quite noticable on some rolling road charts that there were two drops in the power curves, each for about 200 rpm which just happened to corespond to 56 mph and 75 mph in top gear so helping with the fuel econonmy figures when tested by the goverment

 

I am sure around Liverpool there must be enough catted centre sections sat around in sheds... that you could borrow of buy.. someone had a complete exhaust for sale on here yesterday for £60..

STi I believe has no cat in the centre.. I presume the Cat would lower the figures you are failing on.. then you can find out what is wrong with the car and fix it once you have is SVA'd and registered etc..

Could it not still be running on 100RON Jap fuel? or would that not effect it?

JGM

PS: I would loan you my centre but I am not near enough..

 

Thanks for that JGM i will try to find a cated c/box and give it a try.

 

anybody else got any ideas ????

 

turn your fuel pressure down just for the test but what ever you do put it back before you use it in anger

stu

 

What diferance would that make to the readings???