O2 sensor life

[Chris142]

I've always heard that 80K is about it for O2 sensors before they begin to get slow. I've got 109k on mine in my Jeep.

Seems to run fine and fuel milage is as bad as it ever was. But I know that they fail slowly so I may not notice them getting slow.

It did pass the Ca emission test last winter w/o any problem. Does this mean that it's safe to assume that they are ok?

The jeep has 4 of them and they are about $150 ea.

 

[StevieC]

I just replaced both of mine even though the CEL wasn't on and 1 had over 320K KM (192K miles) and the other had 240K KM (144K Miles) on it because it kicked the bucket early in my vehicles life.

I replaced mine because I'm trying to troubleshoot a fuel dilution problem that popped up out of nowhere on a recent UOA.

If you aren't seeing fuel dilution in your UOA and aren't seeing problems on your Emission Tests then don't worry about replacing it. (Most likely no fuel dilution if e-test is fine)

Also the ones after the catalytic converter almost never go and last the life of the vehicle. It's the ones before the catalytic that go and are used for fuel economy.

Being a bit of a Chrysler man because my dad is a mechanic and worked for the company for 20 years I can tell you they usually don't go bad often.

Leave 'em in and drive happy. You are more likely to have an EGR valve problem instead.

 

[Chris142]

Originally Posted By: StevieC
You are more likely to have an EGR valve problem instead.


Thanks StevieC. Fortunatly my 02, 4.0 does not have an EGR valve.

 

[StevieC]

You just said Jeep so I wasn't sure. You have valve overlap instead which is good because I find EGR's are problematic on Chrysler vehicles because of their design.

Now that I know you have a 4.0, you should never have an emission related problem with it until the engine is just about dead and that will be in a ton of miles (more than you ever wanted) if you look after it properly.

Can't kill the 4.0's easily. Only trade off is terrible gas mileage.

 

[Chris142]

The only problem I've seen with the 4.0 Jeep emission stuff is the crank case PCV thing. It's not a valve but a small tube and that tube can get plugged up then they blow oil into the airbox.

 

[StevieC]

Yeah I have seen that but it's rare... It's usually because people over extend their oil changes a few times and the junk gets caught in there... Us BITOG-ers I'm sure it never happens to.

 

[HTSS_TR]

Last year I replaced 2 out of 4 O2 sensors in '94 LS400 with 230+k miles and in '00 E430 with 110+k miles, because CEL of both cars were on and point to O2 sensors.

If no CEL, don't need to replace O2 sensor(s).

 

[Scott_Tucker]

I have replaced a ton of Jeep and Chrysler O2 sensors. Not their fault though as they don't manufacture them. The sensors on any make vehicle can fail. They are usually made by either NTK or Bosch from the factory. I wouldn't worry about yours if you are not having any problems. OBDII *should* tell you if they are getting too slow.

 

[StevieC]

Originally Posted By: Scott_Tucker
I have replaced a ton of Jeep and Chrysler O2 sensors. Not their fault though as they don't manufacture them. The sensors on any make vehicle can fail. They are usually made by either NTK or Bosch from the factory. I wouldn't worry about yours if you are not having any problems. OBDII *should* tell you if they are getting too slow.


That is interesting because dad and I have 12 Jeep 4.0's that we serviced regularly until I moved out and they are all high-milers with original O2 sensors.

 

[saberz]

The only emission issue he will have with it, is the cat, and by the time that needs replacing the Jeep will be rotting.

I had 225k on my 94 Wrangler. Original cat and the last inspection showed it was starting to poopy. That was in 07/08 13 years 225k. I think it served its purpose.

 

[mechtech2]

O2 sensors can last a long time, nowadays.
100k is not that big of a deal, anymore.
Without a problem/code at 150k or less, I would not mess with them.

 

[JustinH]

Take a look at rockauto for sensors. I got mine for half what any parts store wanted.

My saturn needed an o2 sensor at 40k miles, it threw a code..

I replaced with a denso brand o2 sensor. 10 minute job..

 

[wantin150]

Lost one on my 03 Toyota Matrix XRS at 34k. The second went at 44k. At 100k now, now issues, yet.

 

[CBR.worm]

It seems to vary a lot by driving style, fuel quality and additives, placement, etc

My last tundra needed both front o2 sensors almost every 30k for over 200k miles. Many of those miles were wide open with a heavy trailer.

My '97 maxima needed them twice in the first 80k (under warranty)

My current G35 I just replaced both front ones due to being over 100k on them. The car ran better after the swap, but no CEL

My '00 maxima I stopped replacing the o2 sensors after a while and just lived with the light. In that car I replaced them multiple times, but always due to a heater problem.

In my grand voyager I had to replace the engine before the o2 sensors.

 

[firefighter]

Around 120K most sensors are about due. Just cause the light isn't on doesn't mean that they aren't slow. If you notice a differance by changing your 02s they were pretty bad. The only way to really check an o2 is with a lab scope your rich to lean switch should be about 2ms. You normally only have to worry abouth your front o2s as they are the most important for fuel control. However on most late models they are using the rear o2s for fine tweaking of the fuel control, so the back ones are no longer there just for cat monitoring. On your modern cars the computer can compensate for most wear, but fast o2s and good thermostats are two of the biggest items for engine longevity, you may never feel a differance but when you have fast accurate fuel control it makes a differance.

 

[SteveSRT8]

Originally Posted By: mechtech2
O2 sensors can last a long time, nowadays.
100k is not that big of a deal, anymore.
Without a problem/code at 150k or less, I would not mess with them.


I'm in this camp. They go a LONG time and do not require routine changing.

No one arbitrary mileage is possible to recommend replacement because of variances in duty cycle.

 

[ARB1977]

My Tacoma had a check engine light last week for the first time. Bank 1 sensor...changed it out all is good now.

 

[defektes]

Originally Posted By: StevieC
Originally Posted By: Scott_Tucker
I have replaced a ton of Jeep and Chrysler O2 sensors. Not their fault though as they don't manufacture them. The sensors on any make vehicle can fail. They are usually made by either NTK or Bosch from the factory. I wouldn't worry about yours if you are not having any problems. OBDII *should* tell you if they are getting too slow.


That is interesting because dad and I have 12 Jeep 4.0's that we serviced regularly until I moved out and they are all high-milers with original O2 sensors.

The O2 on my 94 jeep 2.5 died around 190k miles, replaced it with OEM.

 

[Blumurder]

You would think they would need replacing more often as their location really gets hot.
When added an aftermarket exhaust on the Stang I replaced all of them

 

[Scott_Tucker]

They need to be hot in order to work. A side advantage to that is it burns deposits off to keep them from fouling. However, understandably it is a pretty harsh environment at temps up to 1200 degrees F but they are built pretty stout.