Just passed MOT with very low emissions can I remove the cat

[bigdods]

So the chim just passed the MOT with incredibly low emissions ! Now I know I have a slight leak on the o/s exhaust manifold gasket, but I had even lower readings last year before I had that leak. And these are two different MOT stations. And the previous MOT was just after a rolling road session that showed 260BHP so no loss of power. Is it just me or are all chims this clean ? And looking at the very low numbers I'm wondering it it would pass without any cats at all ! MOT tester did comment it was running incredibly lean (based on these results).

............Limit..........Actual
Fast Idle
CO.....<0.300%.........0.000%
HC.....<200ppm.........9 ppm
Lambda.0.97 - 1.03.....1.027

Natural Idle
CO.....<0.500%.........0.001%

Edited by bigdods on Sunday 9th March 12:06

[dogbucket]

I am no expert but I dont think the cat reduces CO, it is more concerned reducing the hydrocarbons. Your HC figure is similar to mine so I would imagine removing the cat would see this figure go through the roof.

[VictorMeldrew]

I have no probs whatsoever with emissions on my decat 500. Never have.

And cats PRODUCE CO2. Kind of an environmental own goal methinks, but that's a whole other topic. Just don't mention Benzene.

[dogbucket]

VictorMeldrew said:

I have no probs whatsoever with emissions on my decat 500. Never have.

got any figures just out of interest?

Edited by dogbucket on Sunday 9th March 13:15

[redkarla]

I just posted on this topic but the other way round in regards to the one I'm looking at has had them removed after it's MOT and thought it would NOT pass without them? Needs a few things done so maybe just ask an MOT station to test emisions and see what the results are like. Will keep you posted.

[That Daddy]

VictorMeldrew said:

I have no probs whatsoever with emissions on my decat 500. Never have.

And cats PRODUCE CO2. Kind of an environmental own goal methinks, but that's a whole other topic. Just don't mention Benzene.

you sure they are not testing your car as non cat,because they should not benot quite sure how it couldlet me know VictorOh Dogbucket, the cat/s do lower CO but only by a small amount,for example if the car is running at 0.5 CO a cat will usually pull it down to say 0.10/0.20 ish,all approx and obviously variable.

Edited by That Daddy on Sunday 9th March 17:08

[blitzracing]

Double check with VOSA. If the TVR is listed as a car with cat's you will need them legally. Having said that, some car are not listed by VOSA (ie those of very limited numbers or indeterminate origin)then you dont need them. Make the phone call.

Mark

[GreenV8S]

blitzracing said:

Double check with VOSA. If the TVR is listed as a car with cat's you will need them legally.

That's not my understanding. There was a legal requirement for the cats to be fitted when the vehicle was sold. There is no law requiring that they are retained subsequently. It is required to pass emissions tests, and in practice it may be exceptionally difficult to pass without a cat, but there is no explicit requirement to have a cat.

Edited by GreenV8S on Monday 10th March 14:45

[blitzracing]

GreenV8S said:

blitzracing said:

Double check with VOSA. If the TVR is listed as a car with cat's you will need them legally.

That's not my understanding. There was a legal requirement for the cats to be fitted when the vehicle was sold. There is no law requiring that they are retained subsequently. It is required to pass emissions tests, and in practice it may be exceptionally difficult to pass with a cat, but there is no explicit requirement to have a cat.

Maybe I should have phrased it better. Simply if the TVR is not listed by Vosa, even if its post 1992 it may not need to have a catalyst fitted. It depends if TVR submitted the cars spec' before the list was issued, as some small manufacturers did not get their cars included. I cant pass comment on the legality of the emisions simply without a catalyst, if the list says the car should have one. Still worth a phone call.

[GreenV8S]

Quinny said:

So would it pass easier without a Cat then Peter

Ah, I see what you mean!

[spend]

There are VOSA specs for TVR, they have been posted on here previously

Dave