I've got a 2000 Vectra SRI150 which had an engine management light that came on. I took it to my local garage & they put a scanner on it & it came up as P0420. I was advised to fit a new front lambda sensor, which I did. It was new but not a genuine GM part. I've now found that every 70-100 miles or so the light comes back on again, though when i first fitted the new sensor it took a few hundred miles to come on, but it's seems to be getting more frequent. I bought a U480 scanner which works well & turns the light out, but how do I find out why it keeps coming on??
Is it because I used an aftermarket lambda, or is it as someone told me, that it's possibly a temperature sensor playing up? Could it be something else?? This is starting to spoil the enjoyment of using this car, any advice on what I should do next is appreciated
cheers...Nige