I have a 98 explorer sport with 4.0L SOHC V6 that needs oxygen sensor(s). I've been told by Tuffy that with diagnosis of check engine light, there was an error code of P0133. They wanted to replace all of the sensors for $415. Is this necessary? If i wanted to buy the sensors and have them installed, how many are involved? I've been told there are either 3 or 4 to replace and when i looked on the internet to buy them, there are several listed. The explorer runs great, but i need to repair the problem before i can pass an emissions check.
Any ideas?
Thanks,
druggist

 

You only need one at this point and it should cost under $50. You only need the cheapest one, think Autozone had three that would fit. The sensor is on the passenger side exhaust before the cat. If this is your first venture into auto repair you may find it unusually hard to remove. You can not use an open end wrench, it will just round the sensor. If you break the tab off the electrical connector, a box end will fit over the connector. Will probably take a hammer to loosen it. There is a sensor socket that is another option. Heard this is a tough one to get at. You can at least have the shop replace one.

 

If you can change a spark plug, you shouldn't have any problem replacing an oxygen sensor. Make sure that the part you buy has the same connection type as the original else you will have to crimp the old one to the new oxygen sensor. Use a dab of antiseize on the threads but don't get any on the tip of the oxygen sensor or it will be short lived. Spray the connections with electrical cleaner because a bad connection can give you the same service codes as a bad sensor.

 

I just changed the O2 Sensor on my 97 OHV. It had a check engine light and when I downloaded the code it was a "P0141" code. The replacement was not bad but getting to connector was quite a challenge.

My observations:

1) Buy only an O2 sensor with the OEM plug. It was cheaper at Advance Auto parts than the Bosch "Universal" and who wants to cut off the old plug and crimp it on the universal replacement if you don't have to.

2) Spray a little penetrating oil on the old sensor and take a break for about 15 minutes before you try to remove the old sensor.

3) I used a small peg board hook to press into the plug release. This was just about perfect for the job. The 1/8-inch diameter was perfect and it was compact enough to work into the tight space. Any piece of wire that can be bent and is about 1/8-inch diameter will do the job. Practice on the new sensor's plug to get the feel for releasing the connector. I had to do this by feel, so a little practice helped.

4) Since I had a new Bosch sensor with the OEM plug, I cut off the locking tab and then I could slide a box end wrench over the plug and get a good grip on the sensor. Hit the end of the wrench a couple of times with a rubber mallet and it came right out. I had a crows foot, but when I tried to get a good bite on the old sensor, I felt like it would slip off before it broke loose.

This is a job most can do and is no more complex than changing sparkplugs.

Regards ................ JP