Question about Oxygen Sensor on Catalytic Converter....

Hello to all!
I'm a new member here, and need all the help I can get when it comes to anything mechanical.. Hoping you guys can help!
Awhile back my engine light came on.. I took it to Auto Zone and they did a readOut on what was wrong, which indicated I had an issue with my oxygen sensor.. I did not try to fix or replace the sensor at that time, but instead used some really good product (according to everyone I've talked with) called CATACLEAN by Mr. Gasket.. After the folks at AZ reset my engine light, I put a bottle of this stuff in and it seemed to be doing it's job well... After a couple of tanks of gas, the light came on again.. I again used the above, and this time the light came back on after about one tank.. After talking with a friend, he said that it seemed unlikely that this stuff would fix my problem, so I've now ordered an O2 sensor for my truck through Ebay..........and am currently waiting on it to arrive..
My question is, how difficult is it to replace one of these sensors and what would be a reasonable price if I were to have it done by a mechanic...? I would appreciate any info on this or help in any way.. As I said, I'm pretty bad when it comes to mechanical issues.........but I have some friends who are not...
Thanks again in advance for any help you guys might have on this...!

 

It's super simple to do yourself. Unplug, unscrew the sensor. Reverse the process with the new one..

 

Thanks AaronK for your reply back.. Your note makes me feel better about the situation overall here..
I just read a few posts on O2 sensors after searching the term in question, and it sounds like the error codes are very important to determine the exact problem.. I just looked on my printout from Auto Zone and it says the following.. Hoping this helps with regard to all of this....
Error Codes Read
P0136-HO2S-12 (Bank 1 Sensor 2) Circuit Malfunction
P0136-HO2S-12 (Bank 1 Sensor 2) Circuit Malfunction

I have no idea why the exact same thing was posted twice, but wanted to show the EXACT info shown on my printout...
Thanks again in advance for any further info...!

 

One is probably a "pending" and the second is the actual code. I believe that bank 1 is passenger side but I'm not 100% sure..

 

Maybe @Mike can help or @Nor7 with the chilton manual? Good luck sorry I'm no help.

 

See attached. Pretty easy to replace.

 

Thanks to all of you guys commenting on my O2 Sensor issues.. Now here comes a stupid question, as I just got off the phone with a person who pointed out some potential problems.. My main question here is..........is there more than one size/type of Oxygen Sensor for my truck..? The person on the phone indicated that I would need to know WHICH O2 sensor needed to be replaced.. First of all I was assuming there was only one Oxygen Sensor.. I did look at the schematics from above, and there appeared to be more than one......but I've already ordered one from Ebay.......now praying it's the right one.. If there are more than one, are they all the same size? Please let me know.. Hoping for the best in what I ordered....!
Thanks again for all your help..
S

 

I've gone some O2 sensors in my life. From my experience they should be the same however if there are two different part numbers for the vehicle for the sensors it's because one has/needs a longer cable to connect to the system.

 

You have upstream (pre cat) sensors to control your air/fuel mixture and a downstream (post cat) one for emissions bs.

 

Sensor 2 would be downstream I believe.

 

Thanks to all you guys for your info on this..
The latest here is that I've decided to just take it in to the dealership and have them fix this thing right.. I realize that is likely not the cheapest way to go, but at least they should do it right I'm hoping..
I did want to mention an interesting symptom lately that I've noticed that is going on.. While not overheating, my truck will get up to temp (mid-way up on the heat monitor) now even before driving 1 mile! Is this a typical symptom of an oxygen sensor issue? I was told no by a mechanic that told me straight up he didn't like to work on Toyotas, and further stated that sounded like a head gasket.. Do you guys have any thoughts on his comment, and if the symptom is typical of an oxygen sensor issue? Just wondering what to prepare for when taking truck in on Tuesday....
Thanks again for all your help!

 

I have let the dealership replace mine in the past and the cost is around $300 -$400. I have a 2002 Limited with over 200,000 miles on the clock. I had one converter replaced under warranty at 75,000 miles. The warranty is 80,000 milea or it was at the time. I had a second converter replaced by the dealer at around 120,000 miles and the cost is around $2200. The Toyota converters are higher quality and about twice the cost of aftermarket converters.

I live in Louisville, KY and we get different blends of gasoline in the city limits verses outside Jefferson county. The blends differ according to time of year and the EPA dictates special blends within the city limits. A Toyota service manager told me that gasoline in the Louisville, KY area in his opinion causes early converter failure.

The last time the engine lite came on, I disconnected the battery and waited 10 minutes. I then reconnected the battery and the engine lite went out and has been out over a year. I did this because I had heard of false positive readings and I wanted to be sure that I really had a problem. The engine was running perfectly with no lag in acceleration. If there was a performance issue, I would have gone to the dealer who had performed 99% of the maintenance on my truck up to about 188,000 miles

The danger of a clogged converter is that it can adversely impact the engine just like a potato stuffed up the exhaust. I had a 1997 Mercury Cougar with the sucky 3.8 V-6 that simply shut down while driving about 35 MPH from a clogged converter. No warning lights came on but the engine seemed to loose power about 30 minutes before it shut down. I had a new converter installed but the engine valve train was damaged. I gave the vehicle with 70,000 miles on it to the DAV charity.

I used to trust my Toyota dealer but now I have doubts about their mechanics competence. The do a good job with routine stuff but I would get a second opinion on major items with a high mileage vehicle. I was having a vibration in the drive line at about 187,000 miles and the dealer replaced one U-Joint and the central support. Tundras have 2-piece drive shafts with three U-Joints and a central support. I had other work done in conjunction with this problem and the total bill was over $3000. Everything else (replace window lift motor, brakes, tune up, etc.) was fine but I still had the vibration in the drive line. I took the vehicle back after about 1000 miles and asked them to check the U-Joints again.

The diagnosis was a bent rear axle and the cost to repair was $2500 - $6000 depending on what needed to ve replaced in the differential. I thought about selling the Tundra and test drove another vendor's truck. It just did not feel as good as my 15 year old Tundra so I found a transmission shop (Cottmans on Taylorsville road) that serviced all manner of 4 wheel drive off-road vehicles. They immediately determined that the rear axle and differential were not the problem and had the drive line diagnosed by a specialty shop for balance. The specialty shop, which services 18 wheel trucks, determined that one piece of the two piece drive line was slightly bent. Long story short, Cottmans obtained a new drive shaft section from Dana, who provided the original drive shaft to Toyota, installed three new U-Joints and a central support for a total cost under $800. I have driven the Tundra for about 5000 miles since then and it drives as smooth and without vibration as when the vehicle was new. At 203,000 miles, I plan to keep the Tundra for a while longer.

My Toyota dealer told me that when they put my truck on a lift and ran the engine in drive, they could see a bounce in the driver side rear wheel, hence a bent axle. When Cottmans Transmission performed the same test while I watched, there was no bounce and no bent axle.

I have not been back to my Toyota dealer because I don't trust them anymore. They are either liars or incompetent. I plan to buy another Tundra in the next two years, depending on how my 2002 Limited runs, but not from them. In addition to the 2002 Tundra, I also purchased new a 2007 Camry and a 2010 RAV/4 from them.

 

Hello School Teacher, and thanks for your reply back..
I was thinking of closing out this thread before you responded back, and I am so glad you did as I didn't go to the dealership after all to have them take a look at my problem.. The reason? My engine light just went out on it's own one day for several hours, so the idea that this might be a false reading came to mind again.. I want to be absolutely sure I've got a problem before taking it to the dealership, which no doubt will be big $$$$$ (some of the numbers you threw out by the way were concerning to me, as there is no way I can go that route....).. I will have to find some way to do this cheaper if I in fact do have a problem..
At this point, I have absolutely NO performance issues.. The only thing I want to mention (which I think I mentioned previously) is that the C/H gauge gets to it's usual mid range in like 5 minutes now, whereas before it took 10 or 15.. It's not overheating, but just gets to "normal" temps very quickly.. There might also be a slight gas consumption issue, but if so it's so slight I'm unsure at this point.. Also, I took it back to Auto Zone yesterday and the guy there said that his mother had an issue with an O2 sensor and refused to do anything about it.. Said she is still driving her car with no issues and it's been a year! However, he went on to say that this is not a good idea to do that because if something else were to go wrong, you would not know it due to engine light already being on..
So, I'm wondering, given the above, what you guys think I should do.. I'm getting ready to disconnect the battery as you mentioned above to see if the light goes out after battery is disconnected.. Hoping for the best!
Thanks again to all of you for your ongoing suggestions and information.. Please let me know any further ideas about this if you feel like posting..

 

Skyclad:

I am no expert but my check engine light came on in exactly the same spot on a road after a speed reduction from 55 mph to 35 mph about two years apart. I checked with Autozone and I got catalytic converter codes. By coincidence, I had the battery replaced soon after the light came on and, with the new battery, the light went out and has not come back on in over a 9 months. If the oxygen sensor or the converter is failing, disconnecting the battery will clear the codes and, if there is a problem, the light will come back on with new codes. I think that some of the check engine light issues I have had were false positives due to poor fuel in the Louisville, KY area.

In hot weather, if I pull into an ATM line where the ATM is in the side of the bank building, I turn the engine off. Same is true if I have to idle in a closed area for more than a minute or two. Over the years, I have had the dealer replace oxygen sensors where the check engine light came on while waiting at an ATM or immediately after turning off the cruse control. Now, if the check engine light ever comes on, I disconnect the battery to clear the codes. If the light comes back on, I go to the dealership. I have rarely had to go to the dealership.

In years past, we had no check engine light. Regular maintenance and tune ups seemed to work just fine. Rough engine performance, excessive exhaust smoke and poor gasoline mileage were common signs that something was wrong with the engine. I drove a 1983 Ford van with a 300 cubic inch six and a four speed manual transmission over 331,000 miles with very simple maintenance I performed and a trip to a good mechanic when a major problem developed. Looking back, the majority of trips to the shop were for air conditioner service, a failing alternator and leaking water pump. I changed my own fuel pumps as they were simple engine driven mechanical pumps. Those were the days!

 

thanks so much i need to change mine as well

 

Hi, I had some passenger side cat converter codes in the past on my 2004 4.7 and I changed out the passenger side upstream O2 sensor and the code never came back. Changing out the O2 sensors is easy, cat's are a bit more expensive. Re your quick warm up, are you ascending a hill or elevated roadway right away after startup and running the AC? If so, then you will come up to operating temp pretty quickly.