Oxygen sensor - 07 Camry 4 cyl

[jtmann]

Any guidance on how long these last/if or when to have tested or replace?
Thanks!

[Frank Lee]

I've read they should be replaced at 100,000 miles, but I'd wager most of them go well past that with no ill effect.

[serialk11r]

Does your exhaust smell like unburned gas? Soot in the exhaust pipe? If no don't bother.

[user removed]

It's been my experience that oxygen sensors get "lazy" as they age. They finally get so slow at responding that you get a CEL. I had one go bad in my 02 Insight at 40k miles, but I think it was from oil contamination from the previous owners addition of a K&N air filter which was soaked in oil.

regards
Mech

[hondaguy72]

It really depends on engine condition. Very well cared for vehicles, potentially 100k. Most vehicles, closer to 80k for optimum performance.

[ron]

I read on the interweb that between 70-90,000 is when they should be suspected of needing replacement

[serialk11r]

Originally Posted by Old Mechanic

It's been my experience that oxygen sensors get "lazy" as they age. They finally get so slow at responding that you get a CEL. I had one go bad in my 02 Insight at 40k miles, but I think it was from oil contamination from the previous owners addition of a K&N air filter which was soaked in oil.

regards
Mech

Since you have a lot of experience with cars, I thought I might run my theory with you... If you have a lazy O2 sensor but a clean MAF, that helps a lot doesn't it? My MAF was dirty AND I have 12 year, 140000 mile old sensors, and first tank I got 22 mpg average (with some parking lot start practicing), but I just remember the engine being extremely weird at lower rpms (where I like to drive). Well turns out the MAF was covered in a nice thick layer of black stuff, and as soon as it was cleaned it was 10 times harder to stall the engine from a stop. Just like that, I went from stalling out at lights up to 3 times to never stalling again pretty much. The next tank I had probably wasted just as much fuel doing a "steam clean" as I had on the previous tank in the parking lot, but I got 27 mpg instead of 22.

It would seem to make sense since the MAF reading is essentially the first determinant of fuel injected quantity, and the O2 sensor is double checking, so even if the O2 sensor is old, if the MAF is responding well then the fuel trim shouldn't vary as much right? (that doesn't mean the O2 sensor is giving the correct value of course, and my car still stinks...will change the sensors in a few days).

As far as sensor life goes, my mom's Honda Pilot has a bit under 110k, never changed O2 sensors, exhaust smells like roses compared to my car. It seems to burn a small amount of oil but nothing notable. My car has an early 1ZZ which is known for burning oil in huge quantities. I looked through the previous owner's maintanence logs, and discovered the engine had been burning oil for some time, smog results from the past few years have been pass but way more pollutant than average, and most importantly, the post-cat O2 sensor had died under 2 years ago. The post cat O2 sensor died again just a few weeks after I got the car...

Seems like O2 sensors really hate burned oil.

[user removed]

At 140 k miles (since sold) my 99 Maxima had a CEL for EGR flow. If you are going to clean the EGR passageways, you might as well take a systematic approach and clean everything in the throttle control area. EGR and PCV combine to create a tar like substance in the induction system and this causes most of the problems. I consider it a maintenance issue since you can do nothing to mitigate the accumulation except regular oil maintenance and possibly the use of an effective fuel injection system cleaner. The older pintle type injectors were especially susceptible to accumulations of deposits, but it seems like the advent of more modern designs greatly reduced the deposits.

In Nissans the hot wire MAFs had the same issues as the O2 sensors. Honda seemed to not have the same issues with their MAP sensors. While air mass detection on the intake side determines base mixture ratios, the O2 sensor is the final arbiter or mixture control. In my experience, primarily Nissans, by the time you got a CEL for an oxygen sensor the mileage drop approached 25%. It is not really possible to precisely predict the mileage difference between a new sensor and the unknown quality of an older sensor. It may be possible to determine that with a scangauge, but without a known perfect host for a baseline determination then you are still guessing.

I think the recommendations of others in this thread are probably good. I think my Ranger's sensor is still functioning properly at 125k but suspect it is probably near it's practical limit. I do not know if it is original or not but it looks to be original. I'll probably replace it in the spring when I go to the next step in trying for best mileage compared to the current tank at 33.34 MPG.

In a Honda Civic VX the oxygen sensor is a critical part of the mileage equasion and there still seems to be a difference between OE and any aftermarket sensors.

I always price OE compared to aftermarket but I still get 25% off OE parts so that makes the difference lower and even makes OE parts less expensive in my case.

Hope that helps, but I also hate to recommend any replacement part to anyone unless their is good evidence that the expense is justified.

regards
Mech

[roosterk0031]

I've only replaced one O2 sensor ever, 94 explorer. (250,000 on malibu, 235,000 stratus)

Kristin's Altima is the only car I have underperforming and getting a CEL for vacuum leak I think, fixed one break, but CEL came back a week later. She's getting 6-7 mpg less with it than she did with the Stratus with same drive so maybe it needs some more cleaning (she was proud to get a 25 mpg trip last week).

[mcrews]

on my infiniti 02 Q45, I replaced the two sensors at 210k. did not notice any change in mpg