O2 sensor...important?
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Stick Figure
New member
2002 should not actually have an 02 sensor. It should have an air/fuel sensor, which if not replaced will at the least lead to problems in fuel mileage. If it is the catalytic efficiency sensor, then technically it isn't as important, but if for no other reason, I would replace it to shut the lights off so you know if there is a real problem.
When you disconnect the battery or reset the codes how long does it take to turn the light back on?
When you disconnect the battery or reset the codes how long does it take to turn the light back on?
pauls4runner
New member
a/f ratio sensor (heated 02, 4 wire 02) are before cat they are also called upstream 02s. just a regular 02 also called downstream 02 is after the cat. an issue in any of those will set a check engine light, the check engine light being on will caus vsc, and trac lights to come on. if you have a bad a/f sens I highly reccomend replacing those as soon as possible, they control the air fuel ratio through the computer, they can cause the engine to run to lean or too rich, either way can kill your gas mileage, eventually kill your spark plugs and eventually kill the cats. the after cat 02s dont have as big of an impact as the a/f but it wont be able to tell the computer if it is detecting too rich too lean so the computer can tell if the cat is good or bad.
Spark plug, Spark plug wire, spark plug gap, spark plug cross reference and ignition wires at Sparkplugs.com (awesome customer service btw) and there is a tool to find the right 02 sensor for ya, and am thinking this writeup will help installation: 4x4Wire - Tech: Time to Replace the O2 Sensor on your 3rd Gen Toyota? Doing it myself when it arrives! Been researching this on this site for a while, just hoping to save you some time.
Brilliant
New member
2nd this... pre cats control a/f trims.
Stick Figure
New member
Which is why technically it is a catalytic efficiency sensor just as I said.
techno
New member
The sensor is very, very easy to replace and the parts are just as easy to purchase online. But if you have nowhere to physically do it or just don't want to then that's fine, just don't be afraid that it is a difficult job.
another technical name.
These sensors are known universally as o2 sensors, including every Toyota manual and parts guide available. There's no need to confuse the issue with
another technical name.
the great him
Elite Member
rear o2 sensors do nothing for the running of the motor, they simply are an indicator, they will tell you if your cats are working or not, that is it. they WILL NOT change or affect how the motor runs. ask any tech who knows about multi sensor systems like this. it will just throw a code light if it gets bad. now the down side to that is you will be accustom to the CEL being on and if you do have a more serious thing come up in the future you wont know it(unless you check your codes often) cause your CEL will already be on. the desno or NGK o2 sensor run $85-120 depending on where you get them, and are the only sensors to be used in our trucks
theizzardking
New member
how sure is the op the dash lights are related to a sensor? did he even get the code pulled? just want to make sure we're not telling this guy it's no big deal and something else might be going on all together.....:zoom:
either way, if it's broke fix it.:cowboy:
either way, if it's broke fix it.:cowboy:
pauls4runner
New member
all toyotas, if the cel is on, the VSC and TRAC lights will come on. it doesnt matter what the code is. the computer nows their is a code, the computer registers what the code is but the computer does not know what the code is (it knows the number but not the condition) so they are set to disengage the VSC and TRAC system just in case their is a driveability issue. when the VSC and TRAC systems are disengaged (turned off) the lights for those systems then come on. This is something I have learned in my 3 and a half years as a certified Toyota technician
yes i got the code pulled from an autozone and they told me that the part i needed would be about 179.99 is that a good price or will someone do it for cheaper?