On a 1999 Mercury Marquis, bank 2 sensor 2 is located on the exhaust system after the catalytic converter on the driver's side of the vehicle. This sensor monitors the exhaust gases to help manage emissions and fuel efficiency. To access it, you may need to lift the vehicle for better visibility and reach.
Bank 2 is the drivers side of the engine on your 1999 Mercury Marquis Sensor 1 is before the catalytic converter ( upstream ) Sensor 2 is after the catalytic converter ( downstream )
On a 1998 Mercury Grand Marquis : Bank 2 is the drivers side of the engine Sensor 1 would be in the exhaust close to the engine before the exhaust enters the catalytic converter ( upstream sensor )
On a 1996 Mercury Grand Marquis , 4.6 liter V8 engine : Bank 1 is the passenger side of the engine Sensor 2 would be AFTER the exhaust has passed through the catalytic converter
On a 1998 Mercury Grand Marquis : Bank 1 is the passenger side of the engine Sensor 2 is AFTER the exhaust has passed through the catalytic converter
Bank 2 is the drivers side of your engine , Sensor 1 is in the exhaust before the catalytic converter ( upstream )
On a 1997 Mercury Grand Marquis : Bank 2 is the drivers side of the engine and ------------------------------------------------------------------------------------------ Sensor 1 would be close to the engine before the exhaust enters the catalytic converter Sensor 2 would be AFTER the exhaust has passed through the catalytic converter ( also called a catalyst monitor )
firewall 4 - 8 3 - 7 2 - 6 1 - 5 front of Mercury Grand Marquis
Bank 2 is the drivers side of the engine in a 2000 Mercury Grand Marquis
Bank 1 is the passenger side of the engine in a Mercury Grand Marquis Sensor 1 would be in the exhaust close to the engine before the exhaust enters the catalytic converter ( upstream sensor )
The oxygen sensor for bank 1 sensor 1 for a 2000 mercury mountaineer is on the cylinder #1 side.
P1131 = Insufficient switching O2 Bank 1 Sensor 1 Sensor/lean. Could be a B1 S1 O2 sensor going bad.
Bank 2 is the drivers side of the engine in your Mercury Mountaineer Sensor 2 is in the exhaust after the catalytic converter