failed on emmissions test.

[hipwell]

Mot tester man says that the cat was just doing nothing. Ive had a look under the car and the cat looks faily new. Car is running fine, so i dont think the lambda before cat is failing.

The emmissions light came on a few week ago but turned it off and it never came back on.

All i can think is that its had the cat bashed out. Previous ownder told me itd had a new cat last year, but obviously you dont trust what they say unless youve got a reciept which he didnt.

Any ideas?

 

[iimushroomzii]

Get him to put a different car on the test for you and slide him £20

Or just get a second hand cat off here cheap and fit that

 

[Andrew Cooke]

maybe the cat was too cold? Mine was like that, held it at 3K for a whle and it switched on sorting the emissions perfectly.

 

[hipwell]

he said hed tryed that giving it some revs.

just noticed aswel that now its back from the mot the coolant level has dropped to minumum wheras before it was at maximum?

 

[hipwell]

Just been thinking about this.

My cooling fan like never ever comes on unless i puut the air con on. Even if i let it sit on the drive for ages ticking over.

Does the coolant temp sensor tell the ecu to turn the fan on?

could a dodgy temp sensor effect the emmissions?

 

[hipwell]

thought id bump this thread as ill be fitting the new temp sensor tomorow but want to know if ive wasted my money getting it.

does the temp sensor control the fan?
could it have made me fail mot?
could it still be dodgy even though the dash gauge seems to work fine?

 

[f0xy]

ECU controls the rad fan, its twin speed too. The ECU triggers the yellow relay in the engine fusebox which in turn powers the fan on...

Cooling fan wont make it fail the MOT - it only comes on when the coolant temp gets upto the 'double dots' at the top of the gauge