Replacing O2 sensors

BlackVert

15 Year Member
Oct 3, 2003
5,589
9
98
Bethesda, MD
I have some questions about this topic....

(1) Parts stores say there should be 4 O2 sensors on our cars, 2 before the cats and 2 after them. Mine only has ever had 2. Did our cars really come with 4 O2 sensors?

(2) The best deal I can find is $45 a piece. Is that a decent price for them? They are $75 each at CarQuest!

(3) Any suggestions on removing them? The last time I tried to remove an O2 sensor (2001 Camry), it was next to impossible to remove because of rust.

(4) When putting new ones in, is it OK to coat the threads with oil or anything to make them go in easier?

Thanks in advance! :SNSign:
 
1-only 2
2-$45 each is about what i payed.
3-after it cools,hit it with some penetrating fluid.
rent the 02 removal socket.
clean off o2 bung with brake cleaner before installing new o2 sensor.
4-the new o2 sensor should have a small dab of antiseize on the threads already.
if not,i would add some.
 
PB Blaster is what I use on old ones (thread penetrant). WD should do ok as well.

Like Harvey, I also use a smidge of neverseize on the threads. Just a smidge - don't let it contaminate the sensor. Do this at your own risk.

Harvey's socket method is the common and popular one. If space is tight or you prefer (I hate those sockets), a 22 mm open-end wrench takes them off pretty easy. I prefer this method because torque is applied in the same plane as the fastener head.
 
I popped mine off the other day without issue. I did bang up a knuckle but we must pay the Mustang gods with pain every once in a while!

I used a wrench myself. If it's all rusted then by all means hit them with some PB plaster.
 
Check Rockauto.com, I got 2 Denso O2 sensors from them about a month ago for 67 dollars shipped. They each came with a small tube of copper antiseize too.

There are only 2 on the 5.0. I believe the V6's have 4 sensors. I was confused about that as well and thats what I came up with.
 
when they say 4 its would be for an OBD2 system which we don't have (OBD1). I've always just used a wrench to get them off. Any guy who works on his mustang should have PB Blaster in his garage. that stuff works wonders.
 
Any time I have ever done o2's I just fire the car/truck up for about 3-5 minutes to heat the exhaust up a little just wear long sleeves and you wont burn the piss outta yourself :] makes it pretty easy to get them out imo.