Oxygen Sensors

I know there are 3 oxygen sensors. We bought a Haynes repair manual at Auto Zone and it's very helpful. A 1996 Safari with a 4.3L vortec engines has 4 sensors. 2 on the header pipes and one before the catylitic converter and one aft. You can buy a proper O2 sensor socket or use a good wrench. It depends if it is very seized or not?

call a parts store, and ask for two...when he says HEY MORON THERES ONLY ONE(we love parts guys) then you'll know...but

Everyone should have a manual for their vehicle, and the local library should have a professional shop manual available to make copies of for FREE...make the time to take time to read up on your vehicle, and work like the PRO'S! Good luck :)

Dave

I'm not quite sure what the above post is getting at, but it seems to me he's saying there is only 1 O2 sensor. There are in fact 2 oxygen sensors, an "upstream" sensor and a "downstream" sensor. The upstream sensor is located on the exhaust manifold on the passenger side, if you look down from the top of your engine you can see it near the botton of the manifold. The downstream sensor is located just just after the catalytic converter (which is underneath the truck pretty much in the middle)

2 bolts connect it on top to the back of the manifold. I used a 1" wrench to undo the bottom connection at the bottom of the engine. It does require getting under the car and is easily located and removed. The vaccum hoses will also come off relatively easily and you may find the whole assembly has been choked with carbon deposits. Carb cleaner will dissolve these and then you can reconnect all hoses and lines...best of luck ..it's pretty easy, just time consuming and finding a metric wrench proved futile, thus the 1" wrench for the lower connection.

Underneath the car. On top of the exhaust pipe. About 6 or 7 inches down from the exhaust manifold. You have to jack it up and crawl under it. Put penatrating oil on it and use a box wrench. This is before the cataytic convertor.

There is also a 2nd one after the convertor.

There is a possibility that your O2 sensor is fouled. The O2 sensor is what reads the exhaust air to fuel ratio. Have it checked..........I would have looked at a bad O2 sensor before i replaced a catalytic converter. There are some cars with O2 sensors before and after the cats, and others just have O2 sensors in front of the cats. I am not sure what you have.

there are two 02 sensor one is call upstream .. that's is on the exhaust manifold front engine ... and the other is downstream next to the back of the engine on the exhaust y pipe

YES. That is 1 out of several things that can cause a rough Idle.

However, keep in mind that "faulty" sensors might actually be caused by other things, such as wiring problems, computer problems, injector problems, spark plug problems, throttle body problems, etc. You need to do a proper diagnostic sequence. It is not a good idea to just start changing parts.

The 1996-2001 Elantra's have two sensors the upstream and downstream the upstream sensor is located the exhaust manifold and the downstream is located behind the catalytic converter.

the camshaft position sensor is used to synchronize the fuel injection system with the opening of the intake valves.

It synchs the cam shaft location with the crankshaft location

It can be in a distributor or it can read a tone wheel on the cam shaft.

if the code wasnt cleared by either disconnecting the battery or clearing it with a scan tool then it could take awhile. it will turn off eventually. if you just put a sensor in it without proper diagnosis, there is most likely a different problem that turned the light on in the first place, have the computer scanned and diagnose the problem before replacing parts. it will cost less in the long run. the v6 does have an airflow sensor. its called a "mass" airflow sensor. its located in the air cleaner box. (dont replace it unless properly diagnosed!)

It's threaded into the front of your exhaust manifold.

From what I understand is the boost sensor (little black box with a vac line and a 3 wire connector on it 96 pgt) monitors air pressure inside the intake manifold in order to for the computer to adjust for correct air/fuel ratios. The boost sensor is one of many sensors in the car that work together to deliver the most efficient fuel delivery.

Oxygen Sensor Some vehicles have (2 ) or (4) O2 sensors. If you look inside the engine compartment right on the manifold is one O2 sensor, the other is underneath the vehicle about half way back in relation to the catalytic converter. If you see where the exhaust joints together.

When you start looking at the O2 sensors, they are normally numbered something like "Bank 1 Sensor 1" Bank 1 is on the passenger side; Bank 2 is on the driver's side. Sensor 1 is the upstream sensor (near the frame, between the block and the cat) and Sensor 2 is near the Y-pipe (downstream of the cat).

Normally it is the upstream sensors (sensor 1) that go first. They see the harshest conditions. You will need; Oxygen Sensor Socket Anti-Seized Penetrating Oil Sometimes it will take 15 minutes or take a few hours it depends on your luck...

Yes, it is illegal to operate any vehicle that came equipped with a catalytic converter from the factory with it removed.

Right after the catalytic converter or " downstream " of the converter.

The 1997 Ford Aerostar oxygen sensor is screwed into the exhaust pipe. It is about even with the rear of the oil pan.

From the battery to the starter or a power distribution centre, red is power and black is ground. After the starter or PDC, the wire will change colors and sizes, some have stripes, some don't and sizes vary. It's all designed to help mechanics find problems by crossreferencing the wiring in the car with what they see in the service manual.

It is located underneath above the exhaust closest to the driver side if you didnt know. The cheapest way to do it is using a 22mm wrench and just cut the wires to the plug or you can buy the oxygen sensor removal tool at your local auto parts store and just simply turn till it comes off. You may need to pick up a can of pb blaster or ws 40 or some kind of lubricant to help remove it because it may have rusted over the years and should be cleaned out to prevent future rust. Then simply install the new one.

Oops, I meant which of the five wires? I have subsequently discovered that the IAT is connected to the yellow/red stripe wire. I needed to know this in order to install a "gas saver" resistor on this line. Be advised that such an item does not work. When you cut the IAT wire you will cause your check engine light to come on continuously. To correct this, with the ignition off press and hold the odometer zeroing button. Continue holding and turn the ignition to on for a few seconds. Release the odo button and start the engine. The light should go off in a few more seconds.

Check fuses

They are screwed into the exhaust system.

There's 2- 02 sensors on 1991 Toyota Truck (2.4L 4 cyl- 22RE) One right before the catalytic converter & a second just after. Both are mid-way down the exhaust pipe just past the cabin on driver side. Need to get 2 different sensors & make sure you replace the correct one in the pre or post catalytic converter locations.

Best to jack up & support the truck when working. Note post-cat sensor has a heat shield on it that makes it difficult to reach the 2nd nut hold the sensor in place. Recommend buying new nuts from the dealer to replace the old ones. Standard 12mm wrench/socket will remove both hold down nuts per sensor. Also recommend buying Denso (OEM) or NGK brand sensors. NGK's are more expensive.

Bank 2 is the drivers side of the engine in your Ford Explorer

Sensor 2 is after the catalytic converter ( downstream )