superlight emissions

[SAD !]

My 1998 Superlight R has failed its mot due to high exhaust emissions hydrocarbon, carbon monoxide and lambda.
I've replaced lambda sensor but no difference.
Is the ECU standard or is it modified by Caterham ?
Can the ECU be adjusted ?
Any advice would be appreciated !

[Steveh7]

Something must have changed/worn/broke and it is unlikely to be the ECU. Is the engine and ECU original or modified?

[red_slr]

Can you post the results please?

[SAD !]

Carbon monoxide was 0.91 and hydrocarbon was 925.
Can mixture settings be adjusted with ECU settings ?

[Simon1796]

It can only be adjusted if it had an aftermarket ecu fitted.
If on mems then it's fixed and there must be a fault somewhere causing this if it's past ok before.
Maybe needing a new cat as they can die eventually

[red_slr]

When did you last do plugs?

Has it done much track work, the CAT might be dead as said above.

Any exhaust leaks? (usually shows as pops and bangs)

[Steveh7]

I thought perhaps the cat but that wouldn’t affect the lambda.

[Steveh7]

I thought perhaps the cat but that wouldn’t affect the lambda.

[Trackdayguy]

Before I bought an expensive cat I would have the injectors checked. If the car is over fueling those would be the readings.

Get the car very hot, and wack the cat with a rubber mallet. If the car is doing a lot of town work then the cat can get sooted up, getting it hot and wacking it will go a long way in getting a better reading.

[DVandrews]

Check the throttle body balance, it this is way out then that can seriously affect the fuelling.

Dave

[red_slr]

For injectors you can usually just get them cleaned. They are not expensive anyway on a 20 year old car might be worth changing them anyway.

[SAD !]

Not fitted with CAT but will check plugs and injectors .

[red_slr]

Erm, that might be your problem....

How long have you owned the car?

[Simon1796]

No cat! Perhaps you ought to have said that in the first place!

[V7SLR]

If you don't have a cat you're not going to get through the MOT with the o/e ecu ... can you confirm which ecu is fitted?

[jeremyc]

I think you might need to look at changing your MOT testing station rather than anything on the car ...

[Trackdayguy]

Slip the man a tener, job done.

[jeremyc]

Was the car a kit build, or built by the factory? Was it first used on or before 1 August 1998?

The MOT Manual details the tests that will be applicable to your car.

MOT Manual said:

For emissions purposes only you should treat the following as first used before 1 August 1975:

• kit cars and amateur built vehicles first used before 1 August 1998

Which as far as I can see means that a home build first used before 1 August 1998 doesn't require an emissions test. Regardless, you may be eligible for a less onerous testing regime ...

[Simon1796]

jeremyc said:

Was the car a kit build, or built by the factory? Was it first used on or before 1 August 1998?

The MOT Manual details the tests that will be applicable to your car.

MOT Manual said:

For emissions purposes only you should treat the following as first used before 1 August 1975:

• kit cars and amateur built vehicles first used before 1 August 1998

Which as far as I can see means that a home build first used before 1 August 1998 doesn't require an emissions test. Regardless, you may be eligible for a less onerous testing regime ...

Yes the above maybe why it's got no cat. If it's after that date or factory built then a cat is the only way to get a legal mot. No matter what anyone tells you

[SAD !]

ECU is a MKC 104521 which I think is the same as a Lotus Elise.