Co,mot emissions test fail????

[mcp89]

Hi all, I took my mk1 1.8 16vClio for the mot, and it's failed the emissions on high co, I was pointed in the direction of the cat? After getting under the car I find the cat has been welded to the down pipe and a peice of pipe from the cat back to the back bend, if I take this all of and replace the cat will this solve the problem? Or will I be barking up the wrong tree? Lol cheers, mark

 

[Dan519]

when you say high, how high? what are the numbers?

 

[mcp89]

At 1st fast idle its: 0.82 and at 2nd fast idle it's at 0.99
then natural it's 1.29, would the fact that I left it at the garage the night before make a difference? So they did this pritty much from cold??

 

[Dan519]

I'd say that was still cold when they did it personally.

 

[mcp89]

So if I was to take it back for a re-test after a good run Round, do you reckon it would pass? Cheers

 

[gti6steve]

I'd say that was still cold when they did it personally.

+1

 

[Dan519]

So if I was to take it back for a re-test after a good run Round, do you reckon it would pass? Cheers

should be a lot closer, if not spot on. Lambda sensor would be the next thing I'd change if it still fails

 

[MicKPM]

As above, Danny's advice is sound - get the CAT nice and hot by giving it a "spirited" run or by holding it at 3k for 30secs to a minute before putting the probe up its chuff again which really the MOT station should have tried but some are more interested in getting you on/off the test bay ASAP to get the next one in (££££). If the readings barely move go for a new Ho2 sensor.

 

[mcp89]

Thanks all for you help, I'm all mot passed, thanks