In reference to your old Celica, The 02 sensor may have been the non-heated type sensor(heating elements were installed in newer sensors to get the 02 sensor to operating temperature quickly. When the heating element fails that sets off a code, eventhough the sensor portion that monitors oxygen content is still OK) and the new type of 02 sensor found in the 4Runner is actually called an Air/Fuel ratio sensor which is more sensitive as are more voltage increment values for the PCM to monitor also refered to as a wide-band 02 sensor.

Same thing just happened to me. My first thought was the TRAC and VSC somehow messed up. It turns out they light up as a default setting when the CEL comes on.

When this happens it is usually emissions related. I wish I had a loose gas cap. I had a faulty O2 sensor. Maybe all the lights go on so you will take it in???

http://www.toyota-4runner.org/showth...threadid=31608

thanks for the thread. mine just came on as well.

i will probably take it to the dealership since it is still under warranty.

i have an '06 with 21,000 miles on it. seems like its awful quick to happen.

i will try the gas cap before.

My lights came on for 3 days; now they're off.

Should I still be concerned or do you think there was a glitch in the system?

04 4Runner V6 and driving home all 3 lights came on. Had one of the OS changed about 2 years ago. Is this normal and how many are there? I thought I read somewhere it has 3 or 2 OS? Just cleaned the MAF sensor 5 months ago so I don't think it that. Will top of the tank and check the gas cap. Any help would be appriecated.

I was told there are three O2 sensors on my 4Ruuner and they replace the one that needs replacing. My mechanic also said they go out like that on all makes of cars.

Checking the gas gap is the easiest thing to do, make sure it is tight.

I am not sure why all 3 lights come on, it does tend to get your attention though, doesn't it.

Thanks for the reply and I hope this helps anyone with the same problem. Took it to the stealership today. It was a O2 sensor burned out. I was told their are 4 in total 2 in the upper exhast and 2 in the lower exhast. I have to find my paper work since i had one die on me about 1 1/2 ago. If its the same one I might be able to get my co-pay ($50) back. Luckily I bought the Extracare warranty and if I didn't part was $183 and labor $100 so its a nice chunk of change. I ask is this nomally 50k for one to die and they said don't know so go as early as 5k some last for 100k. My old car never had a problem but I did change both at 50k. I think you can do it yourself but need to know which one to change and maybe a special tool to get it out. Has anyone change one on a 04 V6 4runner?? Thanks in advance.

I have an '02 4 runner with 112k miles and the same thing happened to me about 8 months ago. Dealership said they couldn't figure out why they came on (scary they couldn't figure it out). They said it was a sensor or something. They wanted to charge me $1k or they could just reset the lights which I opted for. Well today the all three lights came on. I read somewhere that you can reset the lights by disconnecting the batter cable which I did and the lights went off. I've read here that it could be a sensor or it could be just from topping off the gas tank.

Am I going to be doing damage by just reseting the light?

Hello all,
I have a 2005 V8, and last 2 months the VSC, Check engine, Track lights all came on. They go out after a while, then suddenly few days later come back on. This cycles like this over a month or two. Currently no lights on. I have 50kmile on mine, and O2 sensors are probably in order to be replaced. I'd give then 40-80k miles for replacement. There are 4 O2 sensors, 2-before the Catalytic, and 2 after the CAT. the 2 before are most critical for air/fuel sensing with the ECU. I am not sure that they are Wide Band sensors, however. (anyone have info on this?). Also O2 sensors can be damaged by additive in the gasoline. Any lead based product, like fuel cleaners/boosters, will degrade the life of the sensors. The before CAT sensors are expensive ($150 for each) while the after CAT is generally cheaper ($50 each) but tend to last longer, as the CAT breaks down/cleans the exhaust.

I think I'll replace mine upfront first in the next few weeks, and see what happens.

No
Wideband Oxygen sensors are not used in our 4th Gen runners. At least not in 2003.

My lights came on today for the first time after having the sensors replaced two years ago. Also the maintenance light came on too. I reset the maintenance light by holding the reset button and turning the ignition key to the on position. I shut down the truck and the next time i turned it on the lights went off, very strange, I think somehow they'll come back to haunt me again. Would a dirty air filter cause this? I haven't cleaned my Volant CAI filter in 3Kmiles so I'll clean it tomorrow, including the MAF sensor to see if they come on again.

I just went through the same problems described above by many folks. One of my O2 sensors failed (58K miles, 04 SR5 V6 4WD). I had my mechanic replace it with the original Toyota part. The check engine light went off. But the two VSC lights come on as soon as the truck moves.

I brought it back to the mechanic to check the codes. He came up with C1336 - ride height recalibration required.

How the *^%$ are these two related. Or, as an engineer myself, why should they be. My dealer wants $96 to reset it. I may try to simply disconnect the battery cable to see if it clears it up. But the lights came on twice after being reset by my mechanic.

Anyone have a similar experience?

Thanks,

Ray

The MAP could cause this (the O2 sensor and MAP sensor) are related if a P0171 is thrown. But a dirty air filter will not.

If the air is restricted then the computer adjusts for this and the fuel management system works perfect.

Okay so I have the same problem (check engine, VSC Off and other VSC light came on) but mine was after I stopped for gas and filled up. The gas cap is on--and when I pulled over to check the gas cap but it seemed snug.

So my question is--is this just REALLY odd timing or do you guys think it may have something to do with the gas cap? I guess my best bet would be to take it to Auto Zone to get the codes checked.

FYI:
I have a 02 Toyota 4 runner. My VSC+Trak off + Check engine light were staying on. My Mechanic pulled the same code from my Truck. My 4 runner has 2 oxygen sensors, one for air/fuel and one for exhaust, I purchased both from toyota dealer for $367.00 and my mechanic installed them for $60.00. I have not had the problem since. Initially Mechanic saw a code that referenced the ABS ECU, but it seems that the O2 sensor (po1135) was also causing the VSC and Trak off light to stay lit as well as the check engine light. I hope this helps someone out there because this problem drove me crazy for months.Tim B.