[FONT=arial, sans-serif]I got P0420 code code I was having my yearly inspection and emissions done. I really can't afford to replace the cat/s so I have decided to try to use the O2 spacers/defoulers I read about on here to eliminate the P0420 cel. My question is what o2 sensors do I use these on? I know I read downstream ones should have these spacers but how many are there and where are they located? Thanks[/FONT]