CO emissions high at fast idle - suggestions?

How High was the CO??

If the engine was running spot on in all respects apart from having a non-functioning Cat, you should see anything less than about 1.5% CO at idle, and anything less than 1% at fast idle, with the HC's less than 150 and 100ppm respectively.

If the figures were higher, then the new cat is working hard to clean up the exhasut but you still have a fundemental fuelling problem which you should sort ASAP as you are likely to knacker the new cat in short order.

Can you tell us what the lambda figure is on your current emissions sheet. this would help grately.

Tim. .

Hi Tim

The emissions sheet is at the garage that did the MoT - they don't seem to give customers a copy - so I cannot give you the Lambda figure (I may be able to get it on Monday if I go back)

I do know that the figures with the new cat were fine at idle but at fast idle they were hovering around 45 (is that ppm?) and only dropped to 30 after a time - with the old cat fitted they were never lower than 75 ppm.

I'm thinking of clearing out all the breathers etc. etc. and possibly replacing the lambda sensor as a start (the car does not burn oil but, when I got it a few months back the oil in it looked like treacle and the filter plainly had not been changed in ages - I did an oil change there and then - would another be recommended ?

Graeme

Firstly the garage is legally obliged to provide you with the emissions print out, pass or fail.

Secondly, i'd suggest that you give the engine a thorough service with repsect to PCV, running temp, HT components, and thorttle body.

We need to know the lambda figure to help further!

Tim..

I agree that it sounds like you are damaging the new cat. The old one was probably knackered by the emissions rather than dying 'of it's own accord'.

Get the problem sorted soon and don't drive it very far.

Alan