Is it ok to replace O2 sensors before they fail?

If y’all don’t know already, I’m all into doing preventative maintenance on my 263k+ mile truck. There’s no telling if the o2 sensors been replaced on the truck and maybe it can use some exhaust work as well. Definitely could use a new catalytic converter at some point. When I get ready to get some exhaust work done I’ll go ahead and replace the starter.

Now, back to the o2 sensors. I was thinking of buying some Denso ones and replacing all 4. I do know that o2 sensors can slowly fail and get lazy over time. It may not always set a CEL (at least that’s what I heard).

Also, please share what you have done with your trucks. What types of preventative maintenance have you done or anything in general that you plan to do (mods/upgrades included).

 

I probably wouldn't worry about something that isn't causing any issues currently. @dirtydeeds any inputs?

 

Pick/set your own maintenance schedule...I stick with manufacturer recommendations. And stretch according to the wallet.

 

Something to remember there is a difference between O2 sensors and air/fuel mixture sensors they look similar but are very different. The O2 sensors are after the cats while the air/fuel sensors are before. If you do replace make sure you get OEM ( Denso)

The air/fuel mixture sensors are also known as wide band O2 sensors

 

Are your cats giving you problems? If your not in a commiefornia I'd save the cash or just gut em

 

I wouldn’t replace unless there is an issue. The 4 sensors are 100$ each for oem/oem adjacent. They don’t do a whole lot other than send a variable amount of voltage to the computer. Replacing is simple though, will need a 7/8th wrench.

 

Yes, they can definitely be replaced before they fail. You can also use an exhaust pressure tester to measure exhaust pressure and determine if you have a clogged up system. The pressure is tested at the sensor ports.

 

If there’s no CEL, yours are still operating within spec. Doesn’t mean they haven’t lost a step. New O2 sensors may improve power and MPG if the old ones are nearing end of service life. Or, you’ll notice no difference at all. If they fail, it’s not a catastrophic stranded on the side of the road at midnight scenario. CEL light comes on, you check it and see it’s for O2 sensors and replace as soon as it’s convenient. Your call.

 

I would, why not? if you are removing every thing on your exhaust and you plan on keeping your truck a while, I would do it.
You know they are going to fail sooner or later.

 

Alternatively you can just clean them

 

This topic of preventative maintenance is always subjective to personal preference and finances. I'm at 280k+ and still have the OEM O2 sensors. My 02 Celica on the other hand has already been through 3 sets due to oil burning, my SC's sensors are the original set and are 30 years old still functioning properly, but those are 2 wire ones.

 

Go ahead and replace them. If you have a data-logging OBD2 reader, you can actually chart the degradation of the 02 sensors over time. I have in the past.

 

I wouldn’t replace until a problem. As mentioned above, it’s not like you’re going to get stuck. Maybe buy if you see them on sale or on a forum where you can save some cash just to have?

 

You asked about preventative maintenance, it really depends on if you are the first owner and know what has been done and when. At that mileage and age I'd be concerned about a whole list of items including but not limited to, all fluids, wheel bearings, u joints, calipers, hoses, belt, starter, alternator, water pump, radiator cap, thermostat, coil packs, plugs, pcv function test, fuel pump, air and cabin filters, maybe A/C clutch depending on the usage, lube door latches, spare hoist, and tailgate mechanisms, maybe even a new blower motor for HVAC, etc. There are simply many components that wear over the years and miles. It comes down to do you want to work on the truck when it's most convenient? How long do you intend to keep it? How important is dependability? How much frame rust is present? What is the maintenance history? Plus your maintenance budget. So ask yourself those questions. Personally, I will try to replace components before failure to avoid having to do so in poor conditions or at inconvenient times and keep the old parts for spares vs. core refunds.

 

All for preventative maintenance. That being said, when I turn 70, should I have the doctor put stints in my heart since I “may” have a heart attack one day? I know it’s a stretch, just adding a little humor , very little

 

Not stints but maybe stents!

 

That may explain the chest pains

 

Sorry for delayed response. I’m the second owner and bought it when it was just a shy over 200k (I normally wouldn’t buy a high mileage vehicle) but I gave this one a chance. I’m not sure how long I want to keep it but as of now longevity is important to me. There’s hardly any rust. The only rust I really see is on the exhaust pipe. Things like the pcv valve, coolant hoses, cap, radiator, water pump, drive/accessory belts have already been replaced. I also replaced shocks and control arms.

I haven’t replaced wheel bearing, alternator, starter, fuel pump, o2 sensors, still have factory exhaust. I drain and filled trans fluid a few times.

 

I have the same amount of miles on my 2007 the only part I have replaced is the alternator @ 220k miles everything else is original including the shocks. IMO the things to keep up on is oil, coolant and timing/serpentine belts

look up the 1 million mile 2007 Tundra that Toyota got from the original owner

 

That’s great! The main reason I replaced my original shocks was to have the Bilstein 5100s and to lift. I replaced my radiator since it had a slow leak and same for water pump. I probably should have went ahead and replaced the alternator while the parts were out of the way. Some people have better luck than others.

 

The advice I got from a Toyota mechanic when I lived in Arizona is to change out the water pump every other timing belt change whether it needs it or not the water pump is behind the timing belt it would suck to change out the timing belt and soon after you have problems with the water pump

the alternator is on the bottom of the engine passenger side and needs to be done through the wheel wheel unless you have access to a lift than it’s not to bad. I had a shop do it back in 2019 it was $700 parts and labor for a Denso 150 amp

 

Send it !