s3rst

ok, its not my car, my mate took for mot on 29th, co at idle was 2.12% with a limit of 0.3%

i serviced it as requested, plugs/leads/oils/filters ect and it went back and still failed. he was told it was the cat, so i changed it then checked gasses at another garage, it was 1.11% and they advised i should of put a landa on with the cat. so i put a landa from the scrappy on and took it to check it again last night, and it was down to 0.23 and passed!

so i rebooked mot retest, took it in, and they r back up again to 1.90%.

took back to the garage that passed it and they failed it also!

its only on idle co that it fails. the cat and landa both seemed to do there job, but over night something has happened to screw it all up again! any ideas?!