I own a 2003 Vibe w 338,+ miles, I took a reading with a scanner and it read "PO 420, Catalyst System Bank 1 Low Efficiency".
Does this mean that I need to replace my converter again?
More than likely yes. It maybe the O2 sensors have you changed them yet?
05 Matrix XR 4WD and 03 Vibe GT
"If you want Government to solve your problems, then you are the problem!" BMSR
Trix MODS: SRI w/ AEM filter, Vibrant/Magnaflow Cat-back, Alutec Lightweight Crank Pulley
GT MODS: Cosmo SRI, DRL, Auto Stop