QuestionHello,
I have a 1996 Town %26 Country mini van. I need to replace the bank one O sensor. Can you tell me where this is located? Any information would be greatly appreciated. Thank you!
AnswerHi Connie,
The bank 1 side of the engine is the right side of it, think of the front of the engine as the side that has all the belts, then the right side is the one closest to the cabin, and there are three cylinders on that side which exhaust together into an exhaust manifold which is connected to an exhaust pipe. There is a similar set up on the left side of the engine (bank 2) which is close to the radiator/front of the van. There are two oxygen sensors however associated with bank 1, one called the upstream (given the #1) and one called the downstream (given the #2). The most common failure occurs to the upsteam sensor, but the code reader may not spell out which sensor is bad. For example the code may have said the "1/1" sensor which is the one I will describe to you. If it didn't then I would assume it is the upstream sensor. That 1/1 sensor is located on the exhaust manifold just where it joins the exhaust pipe. It looks almost identical to a spark plug. The main difference is that it has 4 rather delicate wires coming from its exposed tip, where as a spark plug usually has a connector tip the meshes with a spark plug 'cap' attached to the spark plug wire.
Once you find it, the task is going to be to disconnect the electrically connector that carries the 4 wires and joins them to a single harness (4 wires in a single wrapping. That is usually a pull apart type of action to separate the two halves, but there is likely to be a tab which you gently lift that otherwise helps to lock them together. Once you do that then you need to remove the sensor with an appropriate size box-end wrench, usually about 22 mm. However to use the box end wrench you will want to simply cut the 4 wires to get the half-connector removed so that the box end wrench can slip over the end of the sensor to align with the 'flats' on its side. The sensor however may well be locked into the manifold by rust, so the best thing to do is put some penetrating oil around the sensor/manifold interface and let is soak overnight. Then it is also helpful to have the manifold warmed up by running the engine for a few minutes, then let cool to the point where it is still warm but not so warm as to present a burn risk should you touch it. Then using the exactly correct box end wrench rock it back and forth until the threads begin to release and allow it to be removed by counter clockwise rotation.
It is suggested that the threads of the manifold hole be 'cleaned' with a tap of the same spec as the sensor threads, but that may not be necessary. However the sensor will come with some thread lubricant which should be applied to the threads on the sensor before you attempt to insert it. If it screws in fairly easily and seats all you do is tighten it to about 20 foot pounds which is like that of a spark plug and then reconnect it. You will use an open end wrench of the same size as the box end wrench used for the removal for this part of the job because the electrical connector is too large to fit through the box opening.
Reconnect the two connector halves and you are done.
You will have to decide what approach to take to reach the sensor, from the top or from underneath the van. I haven't personally worked on that job with that vehicle.
Roland
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