After going to the tuners , this is the 2nd test =
-
-
First results show some seriously rich mixtures and that is a direct cause for your high CO. Second results are an improvement over the first one, but it is still running rich.
My first impression is that there is something wrong with your tune.Comment
-
There's definitely something funky going on beyond the cat.
Ours was tested at 0.20% co with actual value of 0.149%
HC ppm max 200, with HC actual value of 0.44. That's with a single box, 3" Milltek downpipe back system and original Milltek sports cat.85 WR Urquattro, 85 20vT International liveried RallyRep
93 MTMS2 Avant
Comment
-
That's amazingly rich. Have you checked you oil to see if it's being diluted with petrol. The engine won t last very long running like this
Nothelle S2 Avant
Black Ur project
Silver Rs2 Project gone
Ocianic Ur project gone
S2 Coupe project gone
Urs6 plus project goneComment
-
I don't know what to do.Comment
-
As it passed it’s MOT last year, if nothing has altered through modifications, I would ‘assume’ something has failed or is failing. What that is, I don’t know, but a decent engineer would be able to diagnose through the fault codes, telltale signs and experience fairly quickly. To go from MOT pass to those emissions figures in 12-months is a marked change…85 WR Urquattro, 85 20vT International liveried RallyRep
93 MTMS2 Avant
Comment
-
The tune maybe
Sent from my iPhone using Tapatalk93 ABY S2Comment
-
Agree with above. Now, be careful when you do actually trace the issue as the adjusted map from Emerald might leave you running lean which could damage your engine. You need to get the car to someone who understands these engines. Pete Berry at White cottage quattros is not far from you? Good place to ask.Nothelle S2 Avant
Black Ur project
Silver Rs2 Project gone
Ocianic Ur project gone
S2 Coupe project gone
Urs6 plus project goneComment
-
Maybe lambda sensor has gone bad.
I've got a standard ECU here, with that on the car you could pull codes with VagcomComment
-
This does point at the Llambda sensosr. Surprised it's not a wideband.1990 B3 2.0 80 quattro.
1992 C4 2.8 Avant quattro
1994 MTM RS2.
1998 B5 TDI quattro Sport.
2000 B5 TQS.Comment
-
Just a bit of info for everyone, if you have a coupé registered on or before 1 august 1995 you can have a non cat test with much wider limits simply by sticking a ADU sticker on the cam cover.
The only engine listed in the ega database for S2 is 3b. So you can point that out to the MOT test inspector.
Here's a link to the inspection manual.
All the info is listed under nuisance.
Screenshot_20231217-095201.jpg
Comment
-
Yes i have read that think my march 1993 ABY missis out but would be happy to be corrected93 ABY S2Comment
-
As long as it's registered before aug 1995 anyone can use this loophole, I have a aby coupé registered April 93.
I fabbed up a v banded cat for the test but turned out I didn't need it.
IMG_20231014_182401.jpg
Very high flow cat on the left!
The stainless core cats really don't get up to temp easily and don't stay hot for long. And they really only work for about 6 months worth of driving before the matrix is not effective.
Ceramic core is what standard cats are made from and easily get to temp and stay hot but are easily damaged. Finding a 3 inch one was a challenge!
I'm based in Bournemouth if anyone wants help with this kind of setup just ask. It's all a hobby for me (out of my 1.5 car garage) so just paying for just materials and argon happy to help.
As to the problem here, any (more modern) standalone should be easily setup to run in closed loop fuel correction to stoic as a !TEMPORARY MAP! for MOT testing using any wideband / narrow band sensor.
Best guess here is bad lambda sensor, be careful of it running rich all the time. It ruins the engine oil fast, if the dipstick smells of v-power time to change even if it looks clean!
Comment
Comment