Went for the mot today only to told it failed due to high emissions. Also noticed really bad fuel economy.

Help needed.the car was remapped before I had it. So not sure if it's that.

Local mappers would t touch it because they don't have the original map. Any advice is welcome

 

just hammer car for 20 minutes so its hot then re test the emissions,common sense

 

Already did. on the way there as the garage was 20 mins away.

 

what were the readings. could be a failed lambda, cat or an air leak. post the failure sheet please

 

Hi the readings are as follows

First idle test
Engine speed 2250-2750
Co max 0.30 0.58 fail
Hc max 200 ppm 61 ppm pass
Lambda 0.97-1.03 0.99 pass

Second fast idle test
Co max 0.30 1.43 fail
Hc max 200 ppm 6 7ppm pass
Lambda 097-1.03 0.95 fail

Car was warmed up then travelled a 20 mins run before the mot.. just checked the front lambda sensor but not too sure if it's a genuine one as there is no markings on it at all. Looks like it's fairly new to me. Thanks

 

It is up to the testing centre when it is tested not someone on a forum to tell the station so you can get it red hot but the testing station will test it to fit in with their schedule.

It would look like a new cat is required.

 

yep those readings look to be a cat problem. its either knackered or wasnt hot enough. although readings we higher on the second test lamda on second test two.

try a lambda first id say

 

front lambda sensor, this fits in with high fuel usage

 

Hi all. thanks for the messages. Will be looking into the front lambda sensor again.