Exhaust System: Hardware
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2002 Mercury Sable, 2002 Mercury Mountaineer, 2002 Mercury Grand Marquis, 2002 Mercury Cougar, and 2002 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
The downstream HO2S may be located after light off catalyst or underbody catalyst. Underbody catalyst may be in-line with light off catalyst, or underbody catalyst may be common to 2 light off catalysts, forming a "Y" pipe configuration.