172 cup failed mot

[jonty172cup]

Hi, 172 cup failed mot today .. some small stuff I knew about and should have fixed (rear number plate light, screen wash not pumping etc) but the main problem was failing the emissions.

Guy said it could be the cat (he wondered if it had been removed) .. it does smell a bit fuelly as if its running rich but it's not all that noise. Any ideas gratefully received. Could it be sensors or do the cats go on these (it's a 52 with 115k on the clock). And if it is the cat, how much do they cost / what are my opions.

Thanks
Jon

 

[harry289]

So has it been de-catted or does it retain the standard Cat?

 

[jonty172cup]

Not de-catted as far as i know. How would i tell?

 

[Mr Plums]

Couldnt the mot tester tell lol.

 

[dannyb]

MOT tester should be able to tell, Maybe the cat is there and he thinks someone has removed its insides?

Anyhow my phase 1 is still on its origional cat but failed on emissions a couple of years ago and a new lambda (sp?) cured it

 

[barker22]

What are the readings of the emissions test, post them up

 

[Dan@SJM]

^ this. Generally, if CO is above 1% it's lambda sensor.

 

[jonty172cup]

Hi,

First fast idle test
Engine speed manual check
CO 1.07 % vol fail (limit min -, max 0.2)
HC 102 ppm pass (limit min -, max 200)
Lambda 1.073 fail (limit min 0.970, max 1.030)

Second fast idle test
Engine speed manual check
CO 0.8 % vol fail
HC 53 ppm pass
Lambda 1.035 fail

Natural idle test
Engine speed manual check
CO 0.06 pass

 

[fiddyspence]

try lambda first as alot cheaper than cat

 

[Dan@SJM]

IMO those emissions aren't far enough out for the lambda sensor. But have a decent diagnostics, you can see what the lambda sensor is doing then.

 

[jonty172cup]

Thanks for responses. Will try local garage as he was very helpful last time I went in.

S o you think really cat then danlp6 ?

 

[Edges]

You could try a good half hour thrashing round some country lanes to get everything piping hot then it might pass. It's been known to work before with these cars. Plus you second fast idle was a lot closer to passing so stands to reason, get it hotter and it might pass

 

[v16daf]

You could try a good half hour thrashing round some country lanes to get everything piping hot then it might pass. It's been known to work before with these cars. Plus you second fast idle was a lot closer to passing so stands to reason, get it hotter and it might pass

Yeah do this, mine failed last year but this year I gave it a good thrashing on the way to the MOT. Passed fine this year