02 sensor replacement help??

I have been searching for awhile and cant find any information on the 2nd gen o2 sensors. every thing I find seems to be for the first gens.

So does anyone have any links or info as to where i can find a video or description of how to replace the o2 sensors? seems likes there's gotta be a video somewhere.

 

From what I know you just have to screw the old ones out, unplug the harness and screw the new ones in and reconnect the harness. As far as the codes im not sure if there is some sort of procedure while doing this like leave the key in ACC position or disconnect the battery and whatnot.

 

I have seen before you need a special tool. I don't have any codes I just want to replace it before I have any problems. It's my understanding they can become less efficient over time and effect has mileage.

 

Rule 1..

If you don't have a problem, don't fix it. Until your check engine light comes on and it says your o2 sensors went out there is absolutely no need to touch them.

 

Do you believe that they don't wear out before they break then? It was my understanding that they do. And it has 110000 miles

 

Is your gas mileage suffering greatly? Is it running rough?

 

My '06 Avalon has 204,000 miles and is still running original AF/O2 sensors. I will change them when I get a related code.

What I would do is remove and clean your MAF sensor with MAF sensor cleaner. CRC makes a good one. That bugger can affect mpg.

 

I'll look into that. I have noticed a gradual loss in mpg over the years. And I'm just trying to pinpoint the caus.

 

I was getting 15mpg before my o2 sensors went out and now with 3 new sensors I still get 15.

 

If you're not getting engine codes the O2 sensors are working as they were designed. You can change them if you like I guess but you're likely to get the same mileage after the replacement.

 

Ok.. I'm going to try cleaning the MAF sensor then see if that does anything.

 

Remember your truck has 110k miles. It will never get original mileage, other mechanical losses contribute

 

wheel bearings will cause drag too and reduce gas mileage when there going out.

 

If a wheel bearing was causing that much drag it would catch on fire..

 

Suit yourself, go change out your sensors and waste money for no result I don't really care

 

Perfect

 

No need for a video. Unplug them, use this socket to remove them and reinstall and plug in.

 

There are number of items that can cause lower mpg:

Ignition system: Coils & plugs (since it's a Coil-on-Plug design, no wires to worry about)
Dirty MAF
Dirty Air filter
Clogged Fuel filter & injectors
Heavier wheels/tires if you have aftermarket wheels
Bad/Clogged cats (although you should get a code)
Increased weight from mods
others?

 

I understand that. It's the loosing mpg between mods over years that makes me think something is getting dirty or wearing out. The spark plugs are pretty new. maybe I will end up cleaning or replaceing something that was fine in the first place I'm not to worried about it. I'll just chock it up to preventative maintenence . I'm going to clean the MAF first and go from there.

 

1. Don't replace an o2 sensor unless you have a code. Why fix it if there's nothing wrong.

2. Our trucks have 4 o2 sensors, so if you get the off brand ones at $90ish apiece, that's a lot of money, again that probably won't do anything. And that's not even going to the stealership.

3. No you don't need a special tool. I went through having to change a couple of mine last year while chasing a code, and just used a regular open end wrench. The one thing you do have to watch for is the threads. One the sensor on my manifold, the threads pulled out completely due to rust/constant exhaust heat and ruined my exhaust manifold. Not cheap to fix.