Hi all Sorry if this has been answered fully previously but is there a complete fault finding write-up on the numerous fault codes that arise from the o2 sensors / catalytic converter? I have spent many hours reading forums and scouring the net for answers but all to no avail. My wife's 2001 Avensis verso 2.0 VVT-i had the CEL indicator come on 3 weeks ago and has fault codes p0420 and p0430 simultaneously according to diagnosis. I have cleared the faults/CEL (using torque app - see below) and they return again after 1-2 hours of driving. The car seems to drive fine and has been very reliable
