Upstream is an O2 sensor located between the engine and the catalytic converter. Downstream is one located behind the converter.
No Bank 1 is the passenger side of the engine in your Ford Expedition , Bank 2 is the drivers side Sensor 1 for both sides of the engine are before the catalytic converters ( upstream ) Sensor 2 for both sides of the engine are after the catalytic converters ( downstream )
On a Ford Expedition : Bank 1 , Sensor 2 ( downstream ) is the sensor for the passenger side of the engine Bank 2 , Sensor 2 ( downstream ) is the sensor for the drivers side of the engine So in short the answer is from the ( drivers seat )
Bank 1 = Cylinder 1/Drivers Side Bank 1 Sensor 1 = Upstream (before cat) Drivers Side Bank 1 Sensor 2 = Downstream (after cat) Drivers Side Bank 2 Sensor 1 = Upstream (before cat) Pass Side Bank 2 Sensor 2 = Downstream (after cat) Pass Side
For a 1997 Mercury Mountaineer ( 5.0 liter V8 ) ( there are a total of 4 oxygen sensors , 2 sensors that are used with the PCM to adjust the fuel ratio that are nearest the engine on both sides , and 2 sensors that are also called catalyst monitors because they are in the exhaust after the catalytic converters ( downstream sensors ) On the passenger side of the engine in a Mercury Mountaineer ( Bank 1 ) Sensor 1 ( upstream sensor ) and Sensor 2 ( downstream sensor ) On the drivers side ( Bank 2 ) Sensor 1 ( upstream sensor ) and Sensor 2 ( downstream sensor )
the two upstream sensors are located prior to the catalytic converter. One under the drivers door and on the right exhaust next to the base of the transmission. The other on the left exaust under the passenger front wheel well. Downstream sensors are after the catalytic converters
There are 4 O2 Sensors on the 1997 GMC Jimmy V6 4.3L. All sensors are accessed from bottom. All sensors are mounted on the exhaust. Three of the sensors are on the Bank 1 side of the engine (Passenger side). Sensor 1 Bank 1 is upstream of Y joint on Passenger Side, Sensor 1 Bank 2 is upstream of Y joint on drivers side. Sensor 2 Bank 1 is mounted down stream of Y before Cat Converter on Passenger side. Sensor 3 Bank 1 is downstream of Cat Converter on passenger side.
Bank 2 is the drivers side of the engine in your Mercury Mountaineer Sensor 1 is between the engine and the catalytic converter ( upstream ) Sensor 2 is after the catalytic converter ( downstream )
The 2001 Chrysler LHS takes 24" drivers side and 22" passenger side replacement windshield wiper blades.
Bank 2 is the drivers side of your Mustang 4.6 liter Sensor 1 is between the engine and the catalytic converter ( upstream ) Sensor 2 is in the exhaust after the catalytic converter ( downstream )
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 )
The 1997 Chrysler LHS takes 24" drivers side and 22" passenger side replacement windshield wiper blades.
You will have to have access to a scan tool. Autozone does this for free. Bank1=drivers side bank2=passenger side sensor1=before Cat convertor sensor2=after Cat. convertor also referred to "up stream" and "down stream" This just means before(upstream) or after(downstream) of the Catalytic convertor Piece of cake