How to lower emissions?

[gaswizards]

Any ideas guys?

[pdh 14a]

An oil change can help slightly.

[gaswizards]

An oil change can help slightly.

That is first on my agenda and a set of plugs!

[chrismisk]

Stick a cat back in and pull it back off after the test

[Dastardly]

New fuel filter

[skyshack]

Absolutely nothing. After failing with 7.5% CO, I got 0.09% CO and 0pmm HC on re-test. The MOT tester shoved his probe in so far it poked a hole in the front corner of the rotten back box so it was breathing MOT test bay "fresh air". He just accepted it. He must have rammed that probe though quite a few back boxes to think it was normal.

So what is your result?
high CO
high HC
or both?

Could be loads of things. First start on page EF&EC-25.

2nd does the car have a lambda?
Proceed to pages EF&EC-26 for lambda sensor. If you follow the lambda mixture check and arrive at "replace ECU" DON'T. Go find and fix the air leak. If you can prove it's the lambda then disconnect it and reset the ECU by unplugging it or removing the battery +ve cable for about 30 sec. Without the lambda it will use the default setting until you can find and fit a replacement. (they were on offer at £10 at europarts) With a default setting it should pass MOT, if it doesn't then something on page EF&EC-25 isn't right and everything in that list needs a re-check.

If you don't have a lambda I would suggest you fix the reason for poor emissions than try to mask them by setting the "mixture" screw using the instructions on page EF&EC-29 if you have a CO meter or page EF&EC 31 if you don't. Chances are with a meter you won't be able to mask the fault. Chances are without a meter you won't get the emissions to pass a MOT.

[gaswizards]

Thanks for the advice sky shack! I'm gonna look into it!

[ANDY black s13]

A dirty MAF element will up CO readings,easy to fix just remove the maf undo 2 screws holding elment into MAF body
, Aerosol carb cleaner/brake cleaner and if your brave wipe it very gently with a cotton bud