Emissions and cat advice pls

[Louise81]

hi, my golf has just failed the mot on emissions the natural idle level has passed, but on slow and fast idle the CO level is 0.38% but the max levels it should be is 0.30%, they advised me to get it tuned so a fella has just been out and he adjusted the airflow meter and changed the HT lead which didnt make any difference he said it needs a new cat, but he also said that the exhaust is blowing in 2 places where the middle pipe joins the back box, does anyone know if just getting these 2 holes welded will be enough to bring the emissions down to 0.30???

[mk1]

Hi Louise81.
If the emissions are to high and the car has a cat, you will not be able to adjust the fuelling as it is controlled by the engine management computer. These faults are hard to fix without checking the live data that the "ECU" is seeing, the CO% to high suggests a rich mixture (or a air leak before the lamda sensor) or the cat was not up to temperature (or gubbed). What car and what engine?.
Steve.

[AudiA8Quattro]

More than likely need to change the lambda probe.

[free]

or try injector cleaner in it, my mate ald car failed, but sum of that it it passed with flying colours

[Louise81]

injector cleaner in where?? sounds worth a try