Changing O2 Sensors

[Bald Jerry]

I am not tripping any codes or anything like that, but was wondering if anyone has changed O2 sensors at a certain mileage? Just changed my buddies that were bad because he failed emmission testing because of them and his gas mileage was crap. After changing them he said he was getting MPG like the day he got it.

I have noticed I am down a little bit and have been keeping tract of it for a very long time.

Anyone got any thoughts to change them at a certain mileage or leave them be until they go bad?

 

[MO Viet Vet]

Year, make, model, engine and current mileage? C'mon man! How old are the ones in there? Change anytime after 60k IMO.

 

[Bald Jerry]

2005 Tahoe that just turned 80K on it. I did some research and agree change them at 60K. A lot of it out there says 100K and found some that said 80K.

They may not be bad yet and tripping a code, but like everything parts wear out and with the heat of the catalytic converter they are deteriorating and not like new by far anymore. They claim from what I read to a 10 to 15 percent MPG increase. I know it is not much and maybe a mile or so more, but it adds up and mine are going in today and I shall see because I have been tracking my MPG for a long time with an iPhone application and MPG is going down from where it was a while back, so my gut feeling is it will be back up again

Plus they are so simple to change too where they are located and why wait for one to fail or go by the what I read everywhere 100K

I am all for what you said and should have changed them 20K ago with it now being almost 10 years old since I got it new.

Besides a few small scratches and a couple dings thing still looks like the day I got it new. Did all the maintenance on it and used synthetic since dumping the oil after 500 miles breaking it in.

Since I kept tract of the MPG for a long time now will run a few tanks through it and post back the results of changing them before they go bad.

 

[Bald Jerry]

Changed these a couple weeks ago and getting these out was easy and did not need the special socket so if you are going to change these on yours not needed. What you are going to need some wire cutter and cut the wires which I know might sound nerve racking not knowing how easy they are going to come out or if you can get them out.

Just a 7/8" closed end wrench after you cut the wires and you can use another wrench for leverage as you are going to need it or a piece of pipe that fits over the wrench. They are tight!!!!

I would have to say the hardest part was when the plug end came out the plastic clip that holds it on to keep the harness secure broke off which is nothing. The drivers side down flow I thought how am I going to even get at that plug but you can reach from the rear over everything and get at it easy.

So far picked up just over 2 MPG doing city/highway combined and curious to see what just highway will turn out to be. Like I said before have been keeping tract of all this via iPhone app since 2013 and have never had this.

So I would say they do not have to trip a code to be going bad and change them for PM. I had just turned 80K on mine and probably should have done it at 60K. I figured I put 80K on it in 10 years and if I can get another 10 years out of this my Son can drive it like I keep telling him...lol..