Failed swedish MOT today...

[Zoltan]

So, today was my first MOT.
Everything was OK except, you guessed it, emissions! I scored a record high HC = >1000ppm at idle. The CO levels were also quite high. Lambda was 0.935 if I remember correctly. The HC values dropped to <60ppm at 2000rpm. I guess this indicates a rich mixture. The idle is a bit rough (800rpm) but it's not stalling or anything (except sometimes when the engine is cold) Also, the cats were at operating temp at the time of the test.
I know cerberas are usually MOT unfriendly, but hese nubers are quite high.

What do you guys recommend, where should I start?
... oh, and it's a 4.2 -96

[alinton]

Some time back there was a thread which alleged that the Cerb was exempt from some parts of the UK MOT.

Can anyone confirm this, and tell me the exact relevant parts of the MOT book where this is referenced?

Mine's up for one next week!

Thanks

Andy

[sonnylad]

Did they check emissions on both cats, as mine only passed on the passenger's side last year.

It may help things if there not too strict.

Edited by sonnylad on Thursday 28th June 21:26

[Ffirg 005]

sonnylad said:

It may help things if there not too strict.

zortan said:

...swedish...

[Zoltan]

Well, they actually tested the emission on both cats, same result on both

[Byker28i]

I'd like to tell you what my 97 4.2 recent figures were, but with the new computerised UK MOT you don't get any form of report these days. All I know is the guy told me it flew through emissions and would put many new cars to shame. I still have the cats in.

[Mars]

Zoltan said:

So, today was my first MOT.
Everything was OK except, you guessed it, emissions! I scored a record high HC = >1000ppm at idle. The CO levels were also quite high. Lambda was 0.935 if I remember correctly. The HC values dropped to <60ppm at 2000rpm. I guess this indicates a rich mixture. The idle is a bit rough (800rpm) but it's not stalling or anything (except sometimes when the engine is cold) Also, the cats were at operating temp at the time of the test.
I know cerberas are usually MOT unfriendly, but hese nubers are quite high.

What do you guys recommend, where should I start?
... oh, and it's a 4.2 -96

You're a bit knackered if you can't access your ECU. My first port of call would be to advance the ignition at the sites measured by a significant amount. I haven't actually tried this on a Cerb yet (within the month I will, for the same reason) but I had great success with this method on a highly tuned 4-cyl engine previously.

[350Matt]

Get yourself a copy of the software and a normal serial lead then do a search on how to set things up, You'll also need a carb / throttle balancing tool ( Gunsons sell them), balance the airflow on both banks first then reset the throttle position sensors using the software.
all of this should make the car run a lot smoother

Matt

[Zoltan]

Thanks for the help guys!
I guess getting the software to work is essential. I'll start from there...

[marcus1970]

350Matt said:

Get yourself a copy of the software and a normal serial lead then do a search on how to set things up, You'll also need a carb / throttle balancing tool ( Gunsons sell them), balance the airflow on both banks first then reset the throttle position sensors using the software.
all of this should make the car run a lot smoother

Matt

Have you got a link for them - I need one too.

MB