i have a 2001 2.2 cdx vectra which has the code p0420 come up i can clear the codefill the tank with petrol and about 20 to 30 lt left in the tank it come up with the code or about the same mileage ?
it was al right till my brother filled ap at a petrol station begining with t the next morning 5 mile down the road it came up on the dash this was last month and about once a week the same code comes up it had a new exhaust system by a previous owner in 2009 (mot) from the manifold to the rear but did no replace the 2 lambda sensors it has done just over 80000 miles
has any one any surgestions / new sensors / spacers on the post lambda