Emissions Failure

[Guest FIRSTBUILD]

had an MOT on my Saxo VTS today and it failed on the emissions the scarry man said it was the worst reading he had seen from a Saxo.Anyone any ideas what is home checkable ? before I have to take it in for a hook up on the dreaded computer.

 

The readings were first fast idle CO 4-43%

HC .884

 

second fast idle CO 3.02%

HC .927

 

thanks for any info.

[enforcer]

Have you got a leak anywhere in your exhaust system? It's amazing how much difference a wheezy gasket can make. Our Rover 618 failed on emissions a year or so ago and the figures went from a clear fail to a clear pass by tightening three nuts!

 

Hope it's this simple...

[Guest stu205]

ditto above, certainly sounds like a leak

[Guest chris brown]

If it is not a leak somewhere and it would have to be a big one then with the HC that high and high CO it almost looks like its either running on 3 or it is low on compression all round (does it use oil?) and its killed (poisoned) the cat.

[Guest FIRSTBUILD]

Chris , cats fine ! the car runs really well and uses no oil , I have had it 6 months and never had to put any in after the oil change.I think the exhaust has a slight blow from the back box but its tiny and you only know its there by the slight black stain.

[Guest tom2b]

My 106 failed on its lambda reading, the plug in the downpipe, straight swap with a new one, makes a lot of difference. Or the ecu could have had a nervous breakdown and be giving it the wrong mixture

[Guest chris brown]

I think the exhaust has a slight blow from the back box

That would only affect the lamda reading. I think your only option is to have a good check round all the obvious points then bite the bullet and get it on to a diagnostic scanner and check for fault codes as it may be a temp sensor or something which is telling the ECU to run rich.