I'd like to replace the o2 sensors in my truck because I suspect they may be the cause of some isolated pinging. Even if they are not the cause, I'll call it preventative maintainance, as the truck has close to 80k miles on the original units.

The truck is an 02 5.4, and I am wondering if there is a preffered brand? Can I walk into Autozone and get Motorcraft brand? Bosch any good? Also, is it true that I only need to replace the two rear ones, as they are the only ones that meter o2? I did a search and also read something about getting the sensors with a longer harness, but didn't quite understand what that meant?

Any insight on replacing these is appreciated.
Thanks
Brian

 

Bosch are fine. replace the front most ones (upstream of the cat)

 

Bosch makes the OEM sensors. AutoZone, Advanced Auto, etc, should all carry them.

Just tell them the info on your truck and they will set you up with the right parts.
Oh yeah, the front ones are the ones you want to replace...

 

You are going to need a 22mm crowsfoot to do passenger side

 

I doubt that the O2 sensors are the cause of your pinging, and my stock O2's lasted until 160,000 miles. I wish I hadn't have changed them cause they were still doing fine.

 

Why not the other ones? Do they not work in conjunction with each other?

 

No. The rear ones only measure catalytic efficiency. They do nothing more. No useful info, unless you have to pass emissions. And you will unless you throw a "catalyst system efficiency below threshold" code, so don't bother replacing them. That's REALLY REALLY wasting your money.

 

Hmmm, good to know. Thanks Chester.

I love this site!

 

Especially since cat efficiency codes are seldom, if ever, caused by the downstream sesnors.

The downstream sensors are tested for proper operation before the cat efficiency test is run. The test protocol is pretty good most of the time.

Steve

 

Chester, that's very interesting that your sensors went 160,000 miles. In the "Chips" section, Troyer fervently recommends replacing the upstream sensors no later than 50M miles. The claim is that they deteriorate and affect the performance of the truck. I'm not at all disputing what you are saying. Just observing how different experiences and recommendations can be. Sometimes it's hard to know what to think. Thanks for the info though. I've been wondering about this subject. More food for thought.

 

I replaced mine at 72000, they never gave me any codes but, I did notice a differnce when I replaced them ... a little more pep

 

From the many posts I've read here, and from my experience with past vehicles, I believe people replace lots of parts way too early. No reason that O2 sensors should'nt last more than 100K on these trucks(mostly stock). And longer.

Brake pads, rotors, shocks, plugs, antifreeze, belt, diff fluid, trans fluid, etc....often gets repalced too soon, IMO. If it makes you feel better, by all means, do it. But mostly it's a placeebo.

I've had O2 sensors, on other vehicles, go past the 150K mark. And were, by all accounts, still good when replaced.

If you know how to do the job, and can do it right, or pay someone else to do it, the only thing hurt by replacing parts early is your wallet. But if you sleep better..............

 

I replaced mine around 100k with no regrets.
Between cleaning my MAF, and replacing the front O2's, my truck has never run smoother.

 

Troyer does this for a living, and he obviously knows more than I do about F-150s. So I can only tell you what I know. I couldn't tell a BIT of difference, when I changed my "160,000 mile" O2 sensors. That doesn't mean that they didn't have diminished efficiency. It just wasn't enough for me to measure with the pump. I highlighted a word that you stated in your previous post. It seems to me, that Troyer is interested in helping people achieve maximum performance. Necessity and performance carry 2 different meanings to me. I didn't measure "before-and-after" performance.

I have earned a new respect for Mr. Troyer, after having talked to him. I know he's a salesman, (and a very good one at that), but he seems to know a large ammount about f-150's. That being said, I still wouldn't change mine (if I could go back in time), because I'm not racing my truck, nor am I "striving" to get good gas mileage. It's hard to fix something if it isn't broke.

My brother's truck had a bad upstream O2 sensor, and it took us a few weeks to fix it. After we fixed it, his mileage didn't increase dramatically (if any). He got 17mpg with it broke!

I say lots of things on here that sometimes contradict other people. Like with a K&N air filter. K&N says they filter more dirt while maintaining a higher flow. I say that the K&N filled my intake and IAC with dirt, and since I switched to motorcraft, the filter stops up faster, and there's no dirt in my intake. You can believe either me or K&N, or neither of us and try it yourself. I just report on what I've observed. Not what I've read, or heard, or what everyone else thinks. I hope it will help somebody out. Like the silencer mod. Don't waste your time. Unless you want an annoying "supercharger" drone all the time.

I would say, Run them until you feel like it's time to change them or they throw a code. But right before you do, make several mpg calculations, and then compare them to your "new O2" mpg results, and report it here.

 

hey my truck was throwing a code today and I went to get it checked out by autozone. They said that my Bank 1 Sensor 1 was bad. Could one of yall tell my what on that is, the longer cord one or the shorter.

p.s. Srry to be off subject but were is the crankshaft postion sensor at. THANKS!!!!