o2 sensor replacement comment

[groze]

The check engine light came on, so I went by my mechanic. He plugged a little device in and said it is an o2 sensor going bad, but doesn't know which one without putting it on the big computer. There are at least 3. What he did is reset the engine warning light & said if it comes on again, call him for an appointment. He also said it was safe to drive if it comes on. I trust my mechanic been with him for years.

However, I have been reading conflicting information on the web. Some say you can go years without replacing an o2 sensor, others say to fix as soon as possible because it would cause damage to Catalytic converter(s). Also, some say you don't need an o2 sensor because the newer Catalytic converters don't need them.

I am going to go with his advice & wait to see if it comes on again.

[sousa632]

See if the light goes back on then take it to your local parts store and get it scanned. MAKE SURE you get the actual code (Pxxxx) and post it here. We can tell you which one it is and what the problem is. Knowing the code and not a generic "it's an o2 sensor" helps wth diagnosis cause a lot of mechanics resort to that when it can be something else and you needlessly spend money on parts and labor to have to do it again down the road to REALLY fix the problem.

You can also look up the code here.. http://www.taurusclub.com/forum/82-m...odes-list.html

As far as the going years without fixing it...... sure you can, BUT it can and will cause more problems in the long run. It's cheaper to replace a $50 o2 sensor than a $400 catalytic converter

[KhanTyranitar]

I deal with emissions and exhaust all the time.

O2 sensors are maintenance items. Running them as long as possible causes problems. It causes carbon build up, poor fuel economy, blocked EGR passages, pinging, etc. It is probably the #1 contributor to a failed catalytic converter. According to most O2 sensor manufacturers, O2 sensors are designed to last between 60,000 - 120,000 miles. The computer does not have a way to cross check the sensors for accuracy, so if the sensor starts to go bad, but still switches, the computer assumes it is accurate, and will do what it says until the limits of the adaptive strategy. The catalytic converter can be seriously damaged long before that every happens.

Anyone who says newer converters don't need them is smoking something questionable. If emissions were not important, then cars wouldn't even have O2 sensors. The catalytic converter requires and accurate O2 sensor to function correctly. There is no such thing as a converter that will work with a bad sensor.

[00tec-satx]

Upstream- replace immediately if old or faulty
Downstream- leave it alone.

[downhill]

+++222^^^^ Change upstream without delay if possible. I found a pair of upstreams at RockAuto for $35 apiece. Made by NGK and branded as NTX. Fuel economy went up 3mpg in the first tank of gas. I changed both upstream and kept others for spares. The gas savings paid for the change~~

[lynks]

ok need to read the O2's real time short term and long term... there are few sensors when age get to them will not toss a code O2's an TSP are two of the most common ones.... now O2's make sure no vacuum leaks or exhaust leaks .... when reading the scanner ST and lt should read +/- 0 @ running temp and idle ..... now about cheaper O2's remember you get what you pay for.... i rather pay more for the OEM then crap shoot on the aftermarkets when it comes to sensors .... as a Tech too many times they are not up to specs to start with ... or premature failure

[groze]

From reading (Not a car guy) the o2 sensors are under the car. This may be a dumb question. Can a rock, rough rail road track or a chuck hole damage or loosen the connection for the o2 senor?

Since the light has not come on again, do I need to worry about it? The reason, I am asking all this. Is the 2006 has less the 30,000 miles and it shouldn't be going bad-any recalls? The previous owner didn't drive it much. We got it so we wouldn't have to keep putting money into another car we had each month. We are now starting with this car. My mechanic also said it has a fuel pump going bad. Car drives fine. We didn't replace the pump.

[soundu]

Originally Posted by groze

The check engine light came on, so I went by my mechanic. He plugged a little device in and said it is an o2 sensor going bad, but doesn't know which one without putting it on the big computer. There are at least 3. What he did is reset the engine warning light & said if it comes on again, call him for an appointment. He also said it was safe to drive if it comes on. I trust my mechanic been with him for years.

However, I have been reading conflicting information on the web. Some say you can go years without replacing an o2 sensor, others say to fix as soon as possible because it would cause damage to Catalytic converter(s). Also, some say you don't need an o2 sensor because the newer Catalytic converters don't need them.

I am going to go with his advice & wait to see if it comes on again.

There seems to be a red flag here. Even most cheap obd2 readers
will give a code that will define which sensor it is. If he knew
it was a O2 sensor, he should have been able to look up the code.
Or at least tell you what the code was.

If it was the cat efficiency trigger, he might have wanted to look at
the O2 sensor readings on a live scanner to figure out if you
had a bad cat, O2 sensors, or both.

If you have a higher mileage Taurus, replacing both upstream sensors
is not a terrible idea. Might actually improve operations a little if the
old sensors were trashed. But it won't fixed toasted cats. Have you ever
had bad head gaskets or any coolant leaks that could have got into the
exhaust?

Do you really have to fix bad cats? If your in a state that does not
have emission testing, no. Will they make the car run better?
No, as long as there not plugged up. But it will pollute more.
And you will have the nasty light glaring at you every time you start
the car

If your a big picture guy, it would help to get the car scanned with
a live OBD2 scanner and see what the O2 waveforms are, and what
the fuel trims are. That will tell ALOT about the condition of things

[groze]

Originally Posted by soundu

There seems to be a red flag here. Even most cheap obd2 readers
will give a code that will define which sensor it is. If he knew
it was a O2 sensor, he should have been able to look up the code.
Or at least tell you what the code was.

If it was the cat efficiency trigger, he might have wanted to look at
the O2 sensor readings on a live scanner to figure out if you
had a bad cat, O2 sensors, or both.

If you have a higher mileage Taurus, replacing both upstream sensors
is not a terrible idea. Might actually improve operations a little if the
old sensors were trashed. But it won't fixed toasted cats. Have you ever
had bad head gaskets or any coolant leaks that could have got into the
exhaust?

Do you really have to fix bad cats? If your in a state that does not
have emission testing, no. Will they make the car run better?
No, as long as there not plugged up. But it will pollute more.
And you will have the nasty light glaring at you every time you start
the car

If your a big picture guy, it would help to get the car scanned with
a live OBD2 scanner and see what the O2 waveforms are, and what
the fuel trims are. That will tell ALOT about the condition of things

I just got the car from a relative a few months ago, basically gave it to me.

The millage is low, it under 30,000. The previous owner didn't drive it much.

I hope it is not a bad cat. My state doesn't have emission testing but a couple of counties do within my state, which I am not in.

However, I just drove it--still no light. I use Shell 87 gasoline. The reason I don't use BP gasoline, I heard on the news that it damaged vehicles. We have a speedway, Swifty, Shell, Krogers, BP, & Village Pantry gas stations.

[soundu]

Originally Posted by groze

I just got the car from a relative a few months ago, basically gave it to me.

The millage is low, it under 30,000. The previous owner didn't drive it much.

I hope it is not a bad cat. My state doesn't have emission testing but a couple of counties do within my state, which I am not in.

However, I just drove it--still no light. I use Shell 87 gasoline. The reason I don't use BP gasoline, I heard on the news that it damaged vehicles. We have a speedway, Swifty, Shell, Krogers, BP, & Village Pantry gas stations.

If the car truly has 30K and has suffered no trauma, the cats and o2 sensors should be OK.

You need to tell us Vulcan or duratec. Have you changed the coolant?
was the degass bottle brown with sludge?

If this car is new to you, i would change the plugs and wires, fuel filter,
air filter, and check all vacuum hoses for cracks or leaks and repair as
needed.

I would also make sure your battery connections are cleaned and NOT
corroded.

bob