I just had the "check engine" diagnositc done - and it's the O2 sensors. Can anyone tell me what good it does to drop a couple hundred buck on these things? Fuel milage? I'm getting about 16mpg.

 

Check out Underdog Racing Development.
One of the guys is a YT local and from what I hear they got some of the best prices for the O2 sensors:

http://www.urdusa.com

 

Depending on your truck, you'll have either one or two.

If you have just one (or the "front one" if you have two) it tells the ECU what the Air/Fuel Ratio is by breathing the exhaust. The ECU then takes that information and adjusts the amount of fuel delivered to the cylinders to get to a specific A/FR of 14.7:1. This is the point where an engine will best in terms of the balance of power and economy.

If the sensor is faulty, then the ECU won't know what to do with the fuel and you can end up running very rich, or very lean. Neither is good... if you run too lean you save fuel but run the risk of burning a hole in a piston. Run too rich and you waste fuel.

What was the actual diag code?


In terms of replacing the sensor, Peter's right, URD has the best prices for factory stock O2 senors. You can spend less on a sensor, but they won't be Denso factory and you'll have to do some work to get them hooked up.

Replacing it on your own is very easy... it'll take longer to get your tools out than to do the actual work.

 

https://www.yotatech.com/forums/show...ight=o2+sensor

buy your O2s from Gadget (peter posted the link above)

 

I knew I had babbled a lot about how an ECU works recently! It was in your thread!

 

Sorry, I'm not sure what truck you are driving, but if you have a Tundra (I think between '00 - '02) there is a TSB on the O2 sensor. I had mine replaced free at about 50K.

 

Thanks for all the input! I have a 2000 Tundra. I've looked under the truck and I have 4 O2 sensors. I'm not sure what the code is, but my mechanic said the fronts where dead.

The truck has 70K miles. I'm guessing that all the sensors should be replaced?

 

Daryl-
Your dealer should replace them for free. The TSB on the 02 sensor is good for all '00 Tundras and is good for 7years/90K miles. If you are the original owner, you should have received a letter from Toyota stating this.

If you already paid to have your 02 sensors replaced, Toyota should refund you. If I remeber correctly, you would need to send a letter to the corporate office with copy of the work order and receipt.

 

THANKS Sumo99! I called my local dealer, and they are going to replace them (both front) for FREE! You saved me a lot of money.

I wonder what else they have extended...... Is there a web site for that?

 

Glad I could help. This is the only item I know of where they actually extended the warranty. All of the other TSB's are only good during their original warranties. If you register over at TS there is an up to date, detailed TSB list for every year Tundra.