MOT Fail - Emissions very high

[crookie]

So took the 182 down for it's MOT today. It's failed on the emissions with the following results;

Fast Idle test
Engine speed 2450-2850rpm - 2574rpm Pass
CO Max 0.20% - 2.65% Fail
HC Max 200ppm - 819ppm Fail
Lambda 0.97 - 1.03 - 0.91 Fail

Second fast idle test
Engine speed 2450-2850rpm - 2571rpm Pass
CO Max 0.20% - 0.87% Fail
HC Max 200ppm - 55ppm Pass
Lambda 0.97 - 1.03 - 0.98 Pass

Natural idle test
Engine speed 650-850rpm - 763rpm Pass
CO Max 0.30% - 0.96% Fail



The differences between the 1st and 2nd fast idle test I find surprising. The garage suggests a new cat first and then possibly Lambda sensors if that doesn't solve it.

Want to get you guys' opinions as sure it's happened to others and don't want to spend unnecessary £££ on the car.

​Thanks

 

[crookie]

Wondering if getting the car red hot before re-testing would bring down the CO levels enough to get it through, or do you think because the readings are so high it wouldn't do it?

​Thanks

 

[Zeitgeist0190]

On 182s you need to stuff a [wet] rag up one of the tailpipes iirc otherwise it'll show a false reading. I'm not sure if that's applicable in your scenario as i'm not sure how the readings are supposed to be - but worth keeping in mind!
Engine should definitely be hot as well, they overfuel at cold which will put your emissions up

 

[Beef-Mc]

Its not decatted is it, first thing to look at it, then look at lambdas then look at getting a new cat.

 

[Harbinger]

Stuff some octane booster in and injector cleaner, rag it senseless for a good while before hand, burn all the crap out. if was Lamda surely a light would be ok and run a bit dodgy, esp with that reading it's well over, the wet rag thing must be a myth otherwise would surely be the most covered topic on here bar Dephasers.

 

[crookie]

Wouldn't putting a rag up one of the exhausts make the reading higher on the other one? Be great if it works!

Exhaust is completely standard... You reckon change lambdas before cat then? Wondering if diagnostic would say what it is exactly? The emissions light is on (orange light, used to flash now it's just on the whole time).

 

[Harbinger]

might be why, get it fault read first, costs around £20 from most places and will tell you what the issue is. Lambda buy a Bosch one for around £60, cheaper than Renought.

 

[crookie]

Think I'm going to get it down to a specialist first - your right, no point replacing something, only to find out it's something else!

 

[nickydownes]

i had the that light on 2 days after i got mine thought it could be cat clogged up so i thought needed to get it really hot to burn eveything out, so i drove around at high revs 3-4000 rpm for about half an hour stoped turned of engine then started again and all lights had cleared.

also car was running a little lumpy after light come on some one mentioned somthing about limp mode ??
i dont know but it worked for me :rasp:

good luck