Why replace both O2 sensors at the same time?

[e rock]

Relatively new rig (96 LX, 160K) that I haven't been able to baseline yet.

So I've got 0130 and 0133 codes popping up consistently about 15 minutes after resetting. I don't seem to have any other issues, so I'm fairly confident that the front O2 sensor needs to be replaced.

I've seen it mentioned here that replacing both is recommended - any reason other than "you're already in there" convenience?

I assume they're different part numbers? Anybody have the numbers handy (no FSM yet)?


Thanks,
Eric

 

[super90]

O2 sensors are a "wear item" and are recommended to be replaced every 75k mi. (if I remember correctly, check the FSM). Consider them part of a really proper tune-up regimen. Simply put, they are providing one set of input for your fuel injection system so it can manage things optimally. Incorrect input data results in less than optimal management.

Sorry, not familiar with those codes as my rig is a '94, pre-OBDII.

Update: Per the FSM, pages MA-2 and MA-4 (Maintenance Schedules A and B respectively), Heated Oxygen Sensors are to be Replace at 80,000 mi.

 

[retrofive]

x2, wear item. If one is faulty the chances are the other is or will be soon. As far while your in there, can't think of much in that area to do.

 

[TrickyT]

O2 sensors are a "wear item" and are recommended to be replaced every 75k mi. (if I remember correctly, check the FSM)...

There's no specified service interval for the O2 sensors, and 75K is way too short of time in my experience. I wait for symptoms of a bad sensor to appear (e.g., codes, MIL, poorly running engine) then replace them both. Call CDan for the p/n's.

 

[Beowulf]

I've seen it mentioned here that replacing both is recommended - any reason other than "you're already in there" convenience?

They are different part numbers if you buy OEM (highly recommended.) I suppose you could replace 2 or 3 spark plugs at a time but everyone replaces all 6 when they do a tune up.

As others have suggested, the O2 sensors wear out. If yours are the originals or if they were replaced as a pair sometime in the past then they have seen exactly the same amount of exhaust gas/heat/rain/salt/vibrations over the years. Logically, they will wear at the same rate so the rear will need to be replaced soon after the front and vice versa. My original O2 sensors were replaced about 2 months ago; 177k miles and started throwing an O2 sensor code around 170k miles.

-B-

 

[nicholas]

I highly recommend only using OEM sensors. I tried to use some bosche before I found mud and they didn't work. I ended up replacing both with OEM from CDan at a reasonable price. I wish I would have done that in the first place.

 

[e rock]

Thanks everybody. I have no idea if or when they've ever been replaced (pulling a service history is on the list), so I guess I'll add both of them to my "to order" list. And I did enough searching before this to convince me not to try anything other than OEM.


A little more searching yielded part numbers (for 95-97):
front 89465-69085
rear 89465-69105

 

[Brentbba]

Call Cdan (cruiserdan) for all your OEM parts unless it's an emergency and you have to go to a local stealership. Best service, knowledge, price and availability of cruiser parts anywhere, period!

On topic of the thread, I have a standing 30K mile order for O2 sensors on my '94 with Dan. Notorious year for O2 sensors...at least on my truck!

 

[retrofive]

FYI, I remember a while back seeing something on a recall or service bulletin on the o2 sensors for 1993. I can't find remember exactly what is was, think it was this:

1993 TOYOTA LAND CRUISER Bulletin - Vehicle TSB ID 184061
http://www.allworldauto.com/tsbs/NHTSA__TOYOTA_LAND_CRUISER_technical_service_bulletin_128459.html


Anyway I called my local dealer, gave my VIN and they said my truck had been taken care in regards the bulletin at 104,000miles.

 

[concretejungle]

if you decide not to use Cdan,

I ordered mine from sparkplugs.com. They carry the OEM O2 sensor for a good price. May want to go ahead and get new nuts for the bolts before you try to remove the old sensor.

 

[cruiserdan]

Replacing "some" of a "set" of anything is like taking a shower and then putting your dirty shorts back on.

 

[Sno bored]

I replaced both of mine last year (thanks CDan) and no more code 0130 or 0133

 

[Brentbba]

Replacing "some" of a "set" of anything is like taking a shower and then putting your dirty shorts back on.

Visual image is NOT necessary Mr. Shaman!

 

[mikedamageinc]

NEW NUTS definitely!

I replaced mine recently and the nuts were so corroded, they were paper thin! the rear sensor can be a pain too with the heat shield blocking the corroded nuts, hard to get vice grips on.

 

[nuclearlemon]

I don't see a reason to replace both right off the bat. the rear one is behind the cat where it sees "cleaner" air. it's there to make sure the first one is doing it's job.

 

[Marco7]

There's no specified service interval for the O2 sensors, and 75K is way too short of time in my experience. I wait for symptoms of a bad sensor to appear (e.g., codes, MIL, poorly running engine) then replace them both. Call CDan for the p/n's.

On the 1991 80 the sensors are to be replaced at 80,000 miles within TEN years, according to the manual... and get this, on Mr T's dime!

I attempted to redeem my sensor service about 16k miles after the 80k mile mark back in 2003. I called the service mgr and told them that this had yet to be done on my LC when I was last there and just wanted to verify that it was covered by Toyota. He said yes, so I set up the appt.
Everything was going fine, I was waiting for about 4 hours when they paged me.
Apparently removing the corroded nuts on the sensors proved to be quite the challenge for the tech working on my truck.
He was only able to replace ONE sensor. The svc writer said they were going to have to cut the pipe on the other and weld in a new piece , but that would need to be ordered from toyota. He said they'd order it that day and began to reschedule another appt for installation when I heard some shouting going on behind the scenes.
Another service writer comes running out to tell me the news, that they would NOT cover the 2nd sensor's parts or labor since A: it's been 16K miles past the 80k mark and B, 10 years had passed and Mr T is no longer on the hook.
I calmly told them that's why I called beforehand to confirm that it was still covered. he stated the svc mgr did not understand the year or mileage so I would only be getting the one sensor for free.
I was okay with that, said thanks and left.

 

[retrofive]

I don't see a reason to replace both right off the bat. the rear one is behind the cat where it sees "cleaner" air. it's there to make sure the first one is doing it's job.

Assuming you have a 95+, the prior both o2 are in front front of the cats .

 

[e rock]

Replacing "some" of a "set" of anything is like taking a shower and then putting your dirty shorts back on.

Apparently I need to rethink my brake light bulb changing method. Now I just feel dirty...

 

[canman]

One of my sensors went bad right after I had my truck undercoated (rustproofed). I later learned after some research that any contaminant (like oil spray) that gets inside the sensor will ruin it. The dealer wanted over CAN$350.00 for one! So I went to an autoparts store and got an NGK/NTK sensor (P/N 24557) with the factory connector for about $80.00 less (still expensive). I didn't replace the second sensor at that time, but the nuts like others have mentioned were in bad shape. It was a few months later that those nuts gave way and the sensor fell off, and was hanging just by the wires. Luckily it wasn't damaged, and the parts guy at the dealer gave me some nuts for free. It's been over a year since I changed it (15K miles), and so far so good, but I agree that while your down there check things out, and if the nuts look bad replace them.

EDIT: My check CEL came on a day or two after my post. This weekend while under my truck greasing the U-joints I decided to have a look at my O2 sensors. I noticed that the four "breather" ports were covered with dirt (especially the rear sensor). I recalled that I had crossed some fairly deep water including a mud pit during some trail runs a few weeks earlier and knew that this where the dirt had come from. Anyways, I took a small (very) screwdriver and cleaned away the dirt from these ports, and guess what - after a few engine start/ stop cycles the CEL is gone!