Report: Rear oxygen sensor can cause emissions failure
Toyota Camry Problem
The rear Oxygen sensors are a critical element in fuel control (unlike other vehicles) and can cause an emissions test failure for high CO and HCs. The sensing element cracks and and reports an erroneous steady state lean condition which confuses the computer, which in turn makes the fuel mixture overly rich.
Visitor, 1998 Toyota Camry, 220,000 mi
Failed smog inspection for high HC and CO
scanned data and found rear o2 reading 0 volts and cruising speed . no codes stored and all monitors ready
replaced o2 and vehicle passed smog