MOT emissions Failure with a 200 Cell Sports Cat - Help!!

[Chris5044]

Hey guys,
My car has only failed an MOT on emissions last week. I raced over to emerald to get the tune on my car adjusted, but even still it was a maybe if it would pass. I have since had the emissions retested and it still fails. I am really stressed and frustrated at this. Since my run around car died and now my S2 is my daily - so I am stuck...

I heard you can have an interchangeable cat fitted for MOT's. Do you have any suggestions or would be able to help please? I am completely grounded now . (I'm based in Guildford Surrey atm).

Seems these sport cats don't work so well.

[Tractor Dave]

Do you still have your original downpipe and exhaust? I have a pair of Coupe cats here you could bolt on for the test.

[nw66]

Do you still have your original downpipe and exhaust? I have a pair of Coupe cats here you could bolt on for the test.

yeah ditto...

[Chris5044]

Do you still have your original downpipe and exhaust? I have a pair of Coupe cats here you could bolt on for the test.

I am not sure, I know its a 2.5 inch exhaust, it might be miltek. I need to look at my reciepts and find out. I know these cars , (just found out) that they need 2x cats in their setup.. If this will work, this will save me!! ill look into that.

[nw66]

Or find a friendly mot centre


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[Chris5044]

Or find a friendly mot centre


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harder to do these days, I found one, but they cant put it through as i've just failed... super stuck right now.

[sal_s2]

The mot place needs to make sure the cat is nice and hot before testing it. I've known some to test the car when not up to temp

[Ian Simmonds]

Have the emission figures it’s achieved notably changed since last year or over the last couple of years? It might not necessarily be the cat, it might be a telltale indication something is sub optimal like plugs, leads, coils or fuel/AFR etc.

[Chris5044]

Have the emission figures it’s achieved notably changed since last year or over the last couple of years? It might not necessarily be the cat, it might be a telltale indication something is sub optimal like plugs, leads, coils or fuel/AFR etc.

I took the car to the tuners yday and tested it. They didnt say anything about this at all. I was told to maybe change the alternator as Im getting voltage jumps up and down of 1Volt. (which can affect the Idle control valve).

Now I am trying to source a decent alternator for this car and that is almost impossible.. As the original bosch one isnt made anymore. Instead Im seeing "ridex" ones on Autodoc... I just need a reputable part.

[nw66]

Reputable tuners ?

[Chris5044]

The tuners are Emerald based in Norfolk who also sell the Emerald ECU, which I have fitted to my car. As originally my old ECU (standard one) blew and that was possibly due to a "made in china" alternator that a mechanic put off the shelf from Bennetts (a car parts supplier).

So a massive wild goose chase , money and issues.... ££££ just need an easy sollution.

[nw66]

What a ball-ache.


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[Tractor Dave]

If you have erratic idle the test will keep failing. Idle needs to be within a certain range to move on to the next stage of the emission test. Is it fail at that point of the high revs point?
So erratic idle might be your idle stabilisation valve. Give it a good clean.
A vac leak somewhere will also cause rich running. Also faulty maf and lambda sensor.
These cars running properly will just pass the emission test without cats.
Did Emerald test your co2?

[Antsa]

Do you have the values from the emissions test? The numbers might help to narrow down the issue.

If you have aftermarket cats I highly doubt there will be a bolt on solution for replacing them, most likely some welding have to be done. I have welded V-bands to both ends of the catalysator so that any replacement I may have to make it's just a little bit easier.

[Chris5044]

Do you have the values from the emissions test? The numbers might help to narrow down the issue.

If you have aftermarket cats I highly doubt there will be a bolt on solution for replacing them, most likely some welding have to be done. I have welded V-bands to both ends of the catalysator so that any replacement I may have to make it's just a little bit easier.

This was the first test, before I went to the tuners