I have two questions as I recently became a new owner of a 1999 Pathfinder.

1. I have to replace the bank 2 downstream oxygen sensor. Which is passenger side if I understand correctly, however I'm having trouble getting the sensor out. I think the cable is clipped onto something and I cant pull it up or pull it down. Anyone got any tips?

2. The only other quirk this car has is shifting into second car is a little rough. It bangs it harder then any other gear except when I give it gas to shift at higher rpm. Is this going to be a issue later on or can I ignore it? The ATF is at the correct level.

Thanks!

The O2 sensor cable has a clip attached to it which is attached to a sheet metal part in back of your motor. In the following link, you can see that clip on the O2 sensor cable of the one I bought for my '02. https://www.amazon.com/Bosch-13650-Orig ... B000BZG74C The clip is pressed into a small hole in that sheet metal part. You should be able to reach your hand into position to feel it but it is almost impossible to remove it intact. No worries though. Since you are replacing the O2 sensor, just yank on the cable and break the clip. A good quality aftermarket O2 sensor, like the Bosch brand I purchased, will have a clip attached to the cable when you buy it. You should be able to reach your hand into position to press the new clip into the hole the old one was removed from.

One tip for removing the old sensor and installing the new one: Tie a long string to the the old sensor connector before pulling the sensor cable down and out from underneath the car. Then cut the string off that connector and tie it to the connector of the new sensor. You can now pull the new sensor cable up from inside the engine bay with the other end of the string. This is much easier than trying to fish it up by hand in a very tight space where the cable goes.

As for the transmission, I suggest draining about 5qts of old ATF from the transmission and then refill it with a gallon of Castrol Transmax High Mileage ATF https://www.amazon.com/Castrol-03518-Tr ... B00T96Q9A6 and a 24oz bottle of Lucas Transmission Fix https://lucasoil.com/products/problem-s ... ission-fix While draining the old ATF, If you see that is is extremely dark, then drain as much as possible until the old ATF stops flowing out. You will need 6 or 7 quarts of new ATF and the Lucas Transmission Fix to fill it back up. Be sure to check the ATF level while the engine is running and after you have cycled the shift lever through all of the gears 1, 2, R, D, holding the shift lever at each position for about 10 seconds before putting it back in Park to then check the fluid level.

If you have left over ATF, now would be a good time to refresh your old power steering fluid as well It uses ATF as the power steering fluid so this is a good way to use up <1qt of leftover ATF and it will help prolong the life of the pump and seals in the power steering system. A turkey baster or manual pump can be used to remove old ATF out of the power steering reservoir.

Fantastic information! Thanks for the help, since this is my "gambler 500" car do you have any recommendations for where or what budget oriented sensor i should get as a replacement? Thanks again.

Rockauto.com has an array of choices from economy to daily driver brands. https://www.rockauto.com/en/catalog/nis ... ensor,5132 Stay away from anything with less than a 1yr warranty. Bosch is my go-to brand for O2 sensors. They are not overpriced and they are very reliable. Since the Robert Bosch Company developed O2 sensors in the '70s, they have a reputation to uphold for their quality. They cost about twice as much as an economy brand but only half as much as other brands that are no better, in my opinion.

Compare the number of wires, then search. Post cat sensors are 4 on my '03, but pre cat ones are only 3 wire. I did I think it was Mustang sensors on the fronts a couple of years ago, ~$16 each, Bosch, and no issues except some wire splicing for the right connector. There are some oddball Titania ones that some late 90s BMWs among others used that aren't interchangeable, but those are unusual and usually more expensive, not less.

nodashi wrote: ↑

Wed Aug 05, 2020 3:56 pm

Fantastic information! Thanks for the help, since this is my "gambler 500" car do you have any recommendations for where or what budget oriented sensor i should get as a replacement? Thanks again.

I second the recommendation for a Bosch replacement but also suggest you consider replacing the driver side sensor at the same time. Odds are it is the same age as the one that's defective and as such, may be on its way out too.