O2 sensors

retiredatfifty

Recycles dryer sheets
Joined
Jun 23, 2011
Messages
81
So the trouble light on my older Chevy pickup has been indicating bad 02 sensor for nearly a year ... haven't got around to putting a new one in yet. Now the wife's newer Kia mini-van is giving us the same code.

Someone told me that sometimes you can get away with just removing them, cleaning them up, reinstalling, and sometimes they will do just fine for a few more years instead of replacing. At about $50 each for the parts on the truck & i don't know how much on the van, thought about giving it a try. Anybody done this?
 
If you have a vacuum leak, this can also cause the O2 sensors code.

I will first check for any vacuum leaks first. Is the sensor a 2 wire or 4 wire sensor:confused:

How many miles on the vehicles:confused:

The best prices for the sensors is on Amazon, check here first.
 
I would bite the bulltet and take to a repair shop. If it is the sensor they can be a bear to get out. Frequently since the are threaded into the exhaust time and high temps virtually weld them in place.
 
A small piece of black electrician's tape can also be used to cover the warning light.
:hide:
 
A small piece of black electrician's tape can also be used to cover the warning light.
:hide:

A genuine multipurpse use.:LOL:


My experience shows, O2 sensors often require a blow torch to heat up, in order to get them out. Bad enough when on the rack, truly a pain while upside down under the car.
 
My experience shows, O2 sensors often require a blow torch to heat up, in order to get them out. Bad enough when on the rack, truly a pain while upside down under the car.
Along with replacing a muffler and removing wallpaper, I'm adding replacing an O2 sensor to my "I'll pay someone to do it" list.
 
Hey, if the lady can do it we should be able to handle it, Chevy pickup P0147 - O2 sensor replacement (and heater test) - YouTube

But yes, they can be a pain to get to and remove. Of all the things I've replaced on cars over the years I've never done an O2 sensor. I would find the online forum for specific vehicle, they often times have the exact instructions for the task and usually and expert DIY type will help out.
 
Lots of things to consider... Unless the truck is really old, it should have a connection for a diagnostic code sensor. The van will definitely have this... a plug under the dash, where a code reader can be attched. Code readers are available for about $60... From the code, best to go to an online forum for your vehicle. A little searching should bring up a good forum with mechanics that can help, usually with good instructions.
One small point before trying to remove the sensor yourself... (wherever it is located). The temperature should be at least $180 degrees. Sensors are installed with a special "glue" that needs to be heated, to release the threads.
Sometimes, resetting the light will solve the problem, especially if it initially came on after long terms of idling. There are or can be other reasons for the light, sometimes caused by faulty or clogged injectors... and even from the sensor itself... which sometimes can be cleaned. In no case use regular cleaner such as a brake cleaner, but an electrical cleaner as available at Radio Shack, or a good automotive store. Cleaning can be a very delicate process.
The location of the rear sensor may be a problem... in some cases requiring removal of the heat shield, and undoing the rear engine mounts to gain access. Every car is different.

Re the vacuum leak... spray brake cleaner or soap on the vacuum connections help in diagnosing this.

My own car has an onboard diagnostic center which allows for pulling codes. I have a recurring O2 sensor problem, which enriches the fuel mixture and reduces gas mileage... (the fuel sensor works with the on board computer to change richness.) if I reset the sensor, the mileage improves, until the next time... sometimes 1000 miles later. The shop "fix" can be from $500 to $1500 and more, and according to the forums, may not fix it, even then. (A known problem on the 1996 SLS).

I'm not a mechanic, so this is just shade tree stuff, but when it comes to the big bucks to fix something that is hard to understand, I feel your pain.

good luck...
 
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I recommend replacing the sensor. Like a spark plug, they become less efficient or fouled as they age and are crucial for proper air/fuel metering. Older vehicles will have one, newer ones have two. Unheated sensors last 30-50k miles, heated up to 100k. The front one is usually air/fuel ratio sensing, the rear emissions duty.
If you can locate the sensor, then you can assess whether it is DIY or a job for the mechanic. Autozone loans the special slotted socket tool to make the job easier. The original sensor should have had high temp anti-seize on the threads for easier removal. If you can change spark plugs, you should be able to tackle the O2 sensor.
 
If you plan to keep the vehicle a while i'd get it fixed. My understanding is that if you let an O2 sensor go unfixed for too long it can cause the catalytic convertor to go bad which costs A LOT more to replace.
 
Agree best to replace. If the pre-catalytic converter sensor, that one tells the engine how much fuel is needed and will affect mileage. MPG will go down. If post-cat this is only for emissions to tell if the cat is doing its job, no effect on mpg.

They can be tough to get out, after all it is right in hot exhaust. Make sure threads on new one have anti-seize on them. Most all new ones i have seen do. It requires special anti-seize so it does not mess up the sensor.

Since the sensor is electric, the take and out and re-install could fix any high resistance since threads are not only holding it in, but also for electrical conductivity.
 
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