MOT - emissions fail

[scooby doom]

Had the car in for MOT this morning and it failed on the emissions!

Car's generally fitted with full de-cat s/s system - headers, up-pipe, 3" downpipe, 3" centre and Prodrive backbox but I have a replacement centre pipe with 200 cel sports cat. This passed the test last year but not this time.

CO max. 0.30% but it was running about 0.55% at first. After a run to heat the cat and a little 'discretion' with the rev range it managed to drop to between 0.40-0.50% and flickered under 0.40% a few times, with a momentary low of 0.35% that couldn't be beat.

The ecu has a dual map so not sure whether high/low boost setting would have made a difference?

So, looks like I'll need to buy a univeral cat and have it put alongside the sports cat to sort this out. Have read conflicting reviews of reducer addititves so not sure about that either.

Edited October 8, 2010 by Scooby Doom

[Alastair]

My dads forester failed on imissions this year,(2.0 turbo s) I went and got some "cataclean" from a shop in paisley, added this and ran 30miles to get it working. The car passed without a problem, mot guy asking how I managed it. Don't know if it wkuld work for you but worth a try maybe.

[Vimmy]

I don't know if this will help any, I had the dreaded MOT on my MY98 last week, which surprisingly passed. I have on a full straight through system and kept back the OEM catted downpipe, which was then refitted for the purpose of the MOT.

My car also has a switchable dual map, which was in the higher boost setting and the emissions were fine on it. If I read it right, the fast idle test returned 0.03% CO and natural idle test 0.15% CO.

The car had on the old system, a centre section which I believed was more of a baffle rather than any sort of secondary cat so I'm not too sure if that could be used instead of the main cat in the down pipe.

The car didn't have any additives added to it before the test and runs on Vpower, but it has done 211k now so I would have expected a higher CO output, but must have been my lucky day.

Cheers,

Col

[scooby doom]

I went and got some "cataclean" from a shop in paisley, added this and ran 30miles to get it working. The car passed without a problem, mot guy asking how I managed it.

Nipped out again this afternoon, picked up some 'Wynns Clean Burn', switched the map to low boost and had another go.... FAIL!!!

I've had a rake in the depths of the garage and found the original down pipe and 2nd cat pipe, so just need to throw them back on to gain the elusive golden certificate.

Having gone through this palaver I've now got a few ideas of how to change/tweak the pipe arrangement to make it easier for next year.

[scouk]

What a mess.. hopefully you can get it through without too much cost

I'd of offered a shotty of my old center cat pipe but it won't fit properly..

(But I see you foudn your old bits anyway...)

Edited to add: Come to think of it.. I assume the exhaust system was checked for leaks as even a small one can screw up the emission test..

Edited October 8, 2010 by ScoUK

[Alastair]

Unlucky with the cat cleaner, the only other quick check I can think of would be to check the air filter is clean and possibly remove for the mot, this can cure the failed reading it runs rich if dirty air filter failing the test.

[scoobywho]

go to a friendly MOT Garage problem solved easilly