Why is this 1999 ford Taurus 3.0 both downstream Oxygen sensors indicating rich All 4 sensors are new and not swapped HELP?
There are more sensors that feed information to the EC ( engine control)computer to regulate the gas mixture. The engine tenperature sensor is an important one. It may be telling the computer the engine is cold. Do some sensor testing work. The computer can be defective. You have to play detective with a volt-ohm meter. You either learn how to find the problem or pay the price to someone who knows how to locate that problem.
Bear in mind the sensors are just a device that reports *data* that it reads. Replacing a sensor is never going to fix the cause of the data triggering the check engine light codes (unless it is specifically about *failing sensors*.)
In addition to the above counsel, search on the code numbers retrieved from the onboard computer (OBD-II).
Then search Taurus + those codes numbers
There are a total of ( 4 oxygen sensors ) according to the engine wiring schematic for the 1997 Mercury Mountaineer in my Haynes repair manual ( 2 oxygen sensors are " upstream " sensors used by the PCM to adjust the air / fuel ratio of the engine ) ( 2 oxygen sensors are " downstream " sensors / catalyst monitors )
There are 2 or 3 oxygen sensors in your exhaust. "Upstream" sensors are located between the exhaust manifolds (headers) and the catalytic converter (usually located on the mid-pipe); "downstream" sensors are located after the catalytic converters. On V6 Mustangs there can either be one or two upstream sensors and usually only one downstream sensor.
Most 4.0L engines with federal emissions have two oxygen sensors located on the exhaust pipe before the muffler. One sensor is mounted before the catalyst (upstream) and one is mounted after the catalyst (downstream). Most 4.0L engines with California emissions have four oxygen sensors. These are mounted in the exhaust manifold area. Two are upstream and two are downstream. There is an emissions label under the hood of the vehicle that identifies the emissions type.
There are 4 sensors, though not all of them are technically called "oxygen sensors. There are two that are upstream of the catalytic converters, one on each bank. Then, there are two more, one after each catalytic converter, that are oxygen sensors, but officially they are called catalyst monitors, because that is the job they are assigned to do. To recap, the two before the cats (or upstream), are oxygen sensors, and the two after…
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…
There are 2 oxygen sensors one upstream and one down stream. Both oxygen sensors are located underneath the van. The down stream oxygen sensor is located behind the cataylic converter near the cross pipe and the upstream oxygen sensor is located in front of the cataylic converter in plain sight. They look like spark plugs with either 8", 12", or 14" wires attached to them. The upstream oxygen sensors is easily located underneath the vechicle…
Where is the downstream heated oxygen sensor heater circuit fault bank for a 1996 ford f-150 in line six cyindler?
There is no such thing as a "circuit fault bank." That was the terminology your scan tool used to tell you that there is a fault in the downstream heated oxygen sensor circuit. There are three sensors screwed directly into the exaust system. Two you will see under the hood, screwed into exaust manifolds. Those are the upstream oxygen sensors. Now get under the truck. Find the lone sensor that looks like the other two…
There are two oxygen sensors. One upstream and one downstream. The up stream is located at the front of the vehicle below the radiator and the other is near the cadillac converter. If u go to o reilleys they have a tool just for removing the sensors otherwise u could use a plyers or a cressent wrench to remove them