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Transmission Pan Drop/Filter Change/O2 Sensor Replacement

No guarantees are made on the results, and anything you do yourself is at your own risk.

Transmission Pan Drop/Filter Change/O2 Sensor Replacement
Wes Stinson

These jobs were by far the least amount of fun Ive ever had.  The o2 sensors  are an easy job that our friends at Infiniti made really hard, and the transmission pan is just downright MESSY!!  5 shampoos to get the ATF out of my HAIR!!!!  Make sure you have plenty of newspaper, cardboard, or I used plastic shrink wrap that was laying around.  Coincidentally, the box that your Tranny cooler came in works very good.

[See also: Transmission Maintenance Guide]


Transmission pan drop:  This was a really easy job and Im not going to go into a lot of details, as this is easy.

There are brackets holding the cooler lines on, two are obvious, and this one:

This is near the drivers side pre cat.

You also must disconnect the cooler line, with a 19mm socket as shown here (on the passenger side)

I also need to add to do this cold (HOT ATF is the only thing that could make this worse), and let the pan drain for a while.  The way the pan is designed, more is held in the front than the rear, so keep it as level as possible.  I would recommend getting some sort of suction device with a small hose to suck out as much as you can.

Once you get the pan out, just replace the filter, with 4 bolts.  I would recommend letting it drain for a while, and move the shifter around and it will start gushing again!!  Would have made it much less messier for me.

Clean the pan really good.  Mine just a gooey metallic stuff on it, and id say thats normal for a car with 127k with only one flush, and thats it as far as maintenance.  Clean the magnet off really good as well as the rest of the pan.

Hardest part of the job was getting the pan back on while balancing the gasket.  My old gasket was caked on there, and it took quite a bit of scraping to get it off.


Oxygen sensors

This is just plain no fun.  I actually only did the drivers side, as I attribute the passenger side to nearly impossible with an o2 sensor wrench (I broke a socket and extension trying to get it out, from the flex joints binding).  I think its impossible without a CROWS FOOT WRENCH (7/8 size), as theres just not enough room.  Someone did it (Q451990 on NICO), and said that it was hard and you just had to cuss your way through it, I didnt agree.  Many hours trying with different setups and couldnt get it to work.

The reason you cant is because once you get the wrench on it, the valve cover is right in the way, and 2 flex joints is the only way you can do it.  A crows foot is necessary, but I didnt buy one because I spent all my money on the wrench, and it would cost me about the same for my shop to change it for me.

The drivers side, was really pretty easy.  Its set at an angle next to the EGR pipe.  I used an o2 sensor wrench, and Id say to do this job the most efficiently you need a crows foot AND a o2 sensor wrench.

Just slide the o2 sensor wrench over the sensor, and then I used a series of extensions and a flex joint in the middle.  it worked great, but its at angle near the brake lines.  I just kept going untli I felt it move.

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