Replace oxygen sensor even if check engine light does not come on
msrdude
never replaced my o2 sensors before and the check engine light is not
on. I was wondering, can the o2 sensor cause my car to get poor gas
mileage and the check engine light will not be on?
Jeff Strickland
"msrdude" <kim...@gmail.com> wrote in message
news:b65d8292-7877-4665...@m7g2000prd.googlegroups.com...
Not bad enough that you'd notice.
If you religiously kept a mileage log and carried it out 3 or 4 digits past
the decimal point, then you might see the O2 Sensor as it failed, but so
many other things affect the mileage that it would be poor troubleshooting
technique to replace the sensor because the 4th digit floated around.
Do not worry about the sensor until the car tells you to worry.
Ray O
"msrdude" <kim...@gmail.com> wrote in message
news:b65d8292-7877-4665...@m7g2000prd.googlegroups.com...
No. The O2 sensors have to be pretty far out of specifications to make a
noticeable difference in fuel consumption, and the check engine light will
illuminate before the sensors get that far out of spec.
--
Ray O
(correct punctuation to reply)
msrdude
air filter, spark plug, spark plug wires, poured in fuel injector and
fuel system cleaner into my gas tank after fill up. It sill made no
difference. So I suspect the o2 sensor is kind of bad causing the fuel
economy to be kind of bad. Well I never replaced the o2 sensor before
and its 125 k miles on it. Well I should replace it anyways because it
is almost due anyways.
Should I buy the NTK o2 sensors or should I go with OEM Toyota?
Mike Hunter
equipment to analyze WHY the check engine light is illuminated and have the
fault corrected, or you can continue to change some very expensive parts,
like the O2 Sensor, until you hit upon the correct part that is causing the
check engine light to illuminate.
The O2 Sensor rarely fails, but it does become contaminated, because of what
could be a minor fault in the closed loop system
"msrdude" <kim...@gmail.com> wrote in message
news:1a09a78d-5841-4338...@k13g2000prh.googlegroups.com...
Ray O
What brand spark plug and spark plug wires did you use?
When you say that the fuel economy is kind of bad, how bad is it?
Toyota does not publish a replacement interval for O2 sensors because they
normally do not need to be replaced unless they are bad. I would be
surprised if a bad O2 sensor made more than a 1 MPG difference, if that.
There are many other things that can cause poor fuel economy that I would
check before replacing the O2 sensor.
Check tire inflation. They should be filled to at least the pressure
specified in your owner's manual, preferably 5 or 6 PSI higher to improve
fuel economy and tire life.
Multiple short trips will result in poor fuel economy because the engine
gets poorer fuel economy while it is warming up.
Does the coolant temperature gauge rise to the halfway point when the engine
is warmed up?
Excess weight in the car will reduce fuel economy so empty unnecessary
cargo.
Jackrabbit starts, unsteady throttle, etc. will reduce fuel economy.
What is the condition of the transmission and automatic transmission fluid?
If you decide to replace the O2 sensors use OEM.
Ray O
"Mike Hunter" <Mikehunt2@lycos,com> wrote in message
news:4b0ae82b$0$22066$ce5e...@news-radius.ptd.net...
> What you SHOULD do is take the car to a competent tech, who has the proper
> equipment to analyze WHY the check engine light is illuminated and have
> the fault corrected, or you can continue to change some very expensive
> parts, like the O2 Sensor, until you hit upon the correct part that is
> causing the check engine light to illuminate.
>
> The O2 Sensor rarely fails, but it does become contaminated, because of
> what could be a minor fault in the closed loop system
>
Check the title of the post - the check engine light is not even
illuminated.
--
Ray O
(correct punctuation to reply)
>
Jeff Strickland
DO NOT BUY AN O2 SENSOR to correct the symptom you are trying to correct.
The O2 Sensor will throw a code if it is so bad to affect the mileage so you
would notice.
If your region has Summer and Winter Blend fuels, the change of the blend
will cause trouble with your mileage. Please define, "kind of bad."
Jeff Strickland
"Mike Hunter" <Mikehunt2@lycos,com> wrote in message
news:4b0ae82b$0$22066$ce5e...@news-radius.ptd.net...
> equipment to analyze WHY the check engine light is illuminated and have
> the fault corrected, or you can continue to change some very expensive
> parts, like the O2 Sensor, until you hit upon the correct part that is
> causing the check engine light to illuminate.
>
> The O2 Sensor rarely fails, but it does become contaminated, because of
> what could be a minor fault in the closed loop system
Mike,
The Check light is not on. The OP has reported poor fuel mileage, and wants
advice on replacing the O2 Sensor to fix the problem.
Mike Hunter
"Ray O" <roki...@NOSPAMtristarassociates.com> wrote in message
news:heeptq$vpc$1...@news.eternal-september.org...
Mike Hunter
parameters, it is designed to illuminate the check engine light to denote
the vehicle could be polluting, but he did not say if it was on or not on in
any event
"Jeff Strickland" <crwl...@yahoo.com> wrote in message
news:heetmf$3n4$1...@news.eternal-september.org...
Ray O
"Mike Hunter" <Mikehunt2@lycos,com> wrote in message
> He did not say if it was on not.
>
the title of the post implied that the check engine light was not on, but
your advice was right on anyway ;-)
Fatter Than Ever Moe
add ethanolized gasoline to the list,
Ray O
"Fatter Than Ever Moe" <HardTimes@TheFarm> wrote in message
news:4b0b911b$0$5356$bbae...@news.suddenlink.net...
Ethanol has been added to gasoline for a pretty long time, so while it
reduces fuel economy, I doubt if that is the cause of the OP's concern.