O2 sensor up stream

The test should also tell you weather it is the up stream or down stream O2 sensor that is not reading, that will tell you if it is the one in the manifold or the one in the pipe after the cat.

o2sensors are located in the exhaust system.you have 4 o2sensors on your car.so you need to know which sensor your looking for.bank 1 sensor 1 is the first sensor in the exhaust pipe on the side cylinder 1 is on.bank 2 is on the side cylinder 2 is on.then you have a sensor before the catalytic convertor and one after the convertor.

LOCATIONS There are different locations in the exhaust system where O2sensors are positioned. The locations have been given numbers and will be used in the accompanying charts to identify the positions of O2sensors in most vehicles. Due to mid-year production changes or factory inconsistencies, all models may not be covered. If a vehicle being serviced is not covered in the charts, inspect the exhaust system (while cold!) in the general locations to find the applicable O2sensors. NOTE: If equipped with dual exhaust systems, there may be up to 4 or 5 O2sensors in the exhaust system. Be sure to locate all of them before commencing with any testing or service. Fig. 1: Location No. 1 - down pipe
Fig. 2: Location No. 1 - typical O2sensor located in the exhaust manifold
Fig. 3: Location No. 2 - left and right banks of a V-type engine
Fig. 4: Location No. 3 - exhaust collector (where more than 1 pipe joins together)
Fig. 5: Location No. 4 - outlet of the catalytic converter
Fig. 6: Location No. 5 - inlet and outlet of the catalytic converter

There should be a total of 4 o2 sensors. 2 are located on the exhaust, before the catalytic converter and the other 2 will be after the catalytic converter. The o2 sensors look like spark plugs with wires.

Take a 7/8" or 22mm wrench and remove counterclockwise, but unplug before removing. Do the opposite to install O2sensor. Some require special sockets to remove due to where the o2 sensor is located. O2 sensors are located on the exhaust near the exhaust manifold before the catalytic converter and just after the catalytic converter.

should be 4. there will be 2 upstreams which will be located one per side of the motor before catalyic conveters and then 2 down stream o2sensors after the cats. hope this helps.

most cars have more then one o2 sensor the o2sensor that reads the oxygen content is the one on the bottom, this one sends a signal to the second sensor on top through the way of the computer in your car.. some cars have 1 older cars
and the new cars can have as many as 5 o2sensors.. this is called an up stream down stream system doesn't use egr valves..
most cars that have 6 cyl or 8 cyl have 1 or 2 sensors on each side .. and 1 or 2 after the cat in your car good luck

those two codes are for the o2 sensors. both are the upstream sensors on the front and rear banks. so they are desinagted bank 1 sensor 1 and bank 2 sensor 1. them most common cause for this is faulty o2sensors , bad gas and of a poor running engine. so if your car runs good (no misfire) and gas is ok then replace the o2sensor witch is the very most common cause.

REMOVAL & INSTALLATION Start the engine and allow it to reach normal operating temperature, then turn the ignition switch OFF. Disconnect the negative battery cable. Open the hood and locate the O2sensor connector. It may be necessary to raise and safely support the vehicle for access to the sensor and its connector. NOTE: On a few models, it may be necessary to remove the passenger seat and lift the carpeting in order to access the connector for a downstream O2sensor. Disengage the O2sensor pigtail connector from the vehicle harness connector. NOTE: There are generally 2 methods used to mount an O2sensor in the exhaust system. Either the O2sensor is threaded directly into the exhaust component (screw-in type) or the O2sensor is retained by a flange and 2 nuts or bolts (flange type). WARNING To prevent damaging a screw-in type O2sensor, if excessive force is needed to remove the sensor lubricate it with penetrating oil prior to removal. Also, be sure to protect the tip of the sensor; O2sensor tips are very sensitive and may be easily damaged if allowed to strike or come in contact with other objects. Remove the sensor, as follows: Screw-in type sensors: Since O2sensors are usually designed with a permanently-attached wiring pigtail, it may be necessary to use a socket or wrench that is designed specifically for this purpose. Before purchasing such a socket, be sure that you can't save some money by using a box end wrench for sensor removal. Flange type sensors: Loosen the hold-down nuts or bolts and pull the sensor out of the exhaust component. Be sure to remove and discard the old sensor gasket, if equipped. You will need a new gasket for installation. Perform a visual inspection of the sensor. Black sooty deposits may indicate a rich air/fuel mixture, brown deposits may indicate an oil consumption problem, and white gritty deposits may indicate an internal coolant leak. All of these conditions can destroy a new sensor if not corrected before installation. To install: Install the sensor, as follows: NOTE: A special anti-seize compound is used on most screw-in type O2sensor threads, and is designed to ease O2sensor removal. New sensors usually have the compound already applied to the threads. However, if installing the old O2sensor or the new sensor did not come with compound, apply a thin coating of electrically conductive anti-seize compound to the sensor threads. WARNING Be sure to prevent any of the anti-seize compound from coming in contact with the O2sensor tip. Also, take precautions to protect the sensor tip from physical damage during installation. Screw-in type sensors: Install the sensor in the mounting boss, then tighten it securely. Flange type sensors: Position a new sensor gasket on the exhaust component and insert the sensor. Tighten the hold-down fasteners securely and evenly. Reattach the sensor pigtail connector to the vehicle harness connector. Lower the vehicle. Connect the negative battery cable. Start the engine and ensure no Diagnostic Trouble Codes (DTC's) are set. Posting pictures next......

The O2 sensor is located on the passenger side of the car. Directly under the front passenger door you will see the exhaust. The wire going up into the floor is connected to O2 sensor 2