12v corsa b 99 failed mot. High CO emmisions

[pdrpaul]

hey guys got a wee 12 v at auction other week! Failed mot today on high Carbon monoxide emmisions. Of the top of my head failed fast idle test max limit 0.300 actual value 0.935 second fast idle max limit 0.300 actual value 0.205 and on natural idle test max limit was 0.500 actual value 1.917 so as u can see it passed second fast idle fine but failed fast idle and matural idle. I checked air filter and tbh its very clean did notice the oil seems slightly over filled going 2 change that and spark plugs and hope for best any u guys have any idea what else it could be??

[johnny]

Take the rocker cover off see if its clogged with old dryed up oil, spark plugs new air and oil filter, emmisions is a badger of a fix tbh is it stanard exhaust, you could try a new cat, clean the egr out, and make sure the engine is pipeing hot when it goes in for test, warmer the engine thinner the oil lower emmisions

[pdrpaul]

thanks mate il check it out! Being a 12v its total diff to my 1.4 8v which i knw fairly well lol. Anyway put cataclean in and took it for a wee italion tune up hard to tell if its made emissions any better but overall defo seems smoother. Il change the oil etc as i said seems slightly over the max limit. Its a very low mileage car 57k and only dne 1700 mile frm last mot so hoping cataclean and blast up m8 has helped. Thanks mate:)

[pdrpaul]

oh yeah its standard exhaust as well. No mods at all. Got any clue in reason it failed first high idle test but passed second high idle test and failed the natural idle test. Lambda and hc were all within limits!

[johnny]

No like said emmissions is somthing you just close your eyes point at somthing and hope its whats wrong sometimes reading the live data from opcom can point to the problem but again not always