Buy a decent 1 or you may as well go to the track and bet on a 3 legged horse......

We had a Saff in a few weeks ago with an air/fuel ratio guage which when we set the car up with the pukka wide band kit showed the "quality" (read as absolute shite)....... it was reading rich when the car was lean.......lol £100 really well spent on that piece of crap