Replace O2 Sensors?

[4.0blue98]

Topped 200k recently on the 4.0 OHV and still put about 200-250 miles a week on it. What's the consensus on replacing O2 sensors as routine maintenance? No issues and about 19mpg right now.

 

[CorbinsRanger]

If it aint broke.....have you replaced your timing chain tensioners yet?

 

[lil_Blue_Ford]

My understanding is that O2 sensors are good for 10 years and the catalyst inside them is used up.

A good scan tool you can check the values O2 sensors and verify if they are still giving good numbers.

I hate changing them. Usually requires heating the bung with a torch and run a thread chase down through after.

 

[4.0blue98]

If it aint broke.....have you replaced your timing chain tensioners yet?

I had planned on digging into this engine when I hit 200k. The timing chain was something I expected to check carefully. Wanted to do a mild refresh. Doesn't seem like to much trouble on the OHV engine. Another project put the brakes on that for now.

 

[4.0blue98]

My understanding is that O2 sensors are good for 10 years and the catalyst inside them is used up.

A good scan tool you can check the values O2 sensors and verify if they are still giving good numbers.

I hate changing them. Usually requires heating the bung with a torch and run a thread chase down through after.

Yeah I hear you on this. Always a pain to change O2 sensors. Especially 25 year old ones. Didn't look to bad when I was under there doing some exhaust work recently. I do have a scanner with live data. I'll have to have a look first.

 

[cbxer55]

My 98 3.0 just turned 186,000 Wednesday. Still has the factory o2 sensors, no plans on changing them any time soon.

But mine is an oddball anyways. EVAP and EGR deleted. Converter doesn't convert any more (can tell by the smell). The monitors are INC. But that's all. No CEL, and no codes when I scan it. Don't know how that works. New computer in January 2017. Got flooded out in 2020, when I drove home from work in a downpour so heavy, thought I was driving in a river. Had to let it sit for four days with the battery disconnected, before it would start. It's been an oddball ever since.

But it runs so damn good! And getting over 20 mpg, it's typically always hovered in the 14 to 16 range. Also used to have to run premium, and preferably 93 octane to stop the ping. I run 8 in it now, no ping.

Weird! But I ain't complaining.

 

[lil_Blue_Ford]

If it aint broke.....have you replaced your timing chain tensioners yet?

Timing chain tensioners are only the SOHC 4.0, he has the OHV. That said, probably still worth checking the timing chain. My 98 donor Explorer for my 5.0 swap had a sloppy timing chain and it made me wonder just what condition the rest of my toys are in.

 

[4.0blue98]

Yeah I planned to definitely check the chain during my "refresh". It does have a guide and tensioner (part nylon) just not as complicated as the SOHC engine.

Think the consensus is to wait it out. These are the OE sensors. The wife's sienna has the OE sensors at over 330k. But it's only an 08.

 

[sgtsandman]

If the O2 sensors are still performing ok and showing good numbers on a scanner, I would let them be.

 

[DILLARD000]

If OxSensors scan okay now, may just want to wait til they dont scan okay.
In the wait, shop for a good price on a new set to have when you do need to swap em out.
A Bosch 15719 with 24i00 0m610 Long Cable+Plug is good to replace any Ford 4WireNarrowBand OxSensor.

 

[thecause17]

My truck has 190k on it and I did them both recently, but the only reason I did them was because I had the trans out and everything was easy to get to so I took the oppurunity to do it. I didn't have any codes or anything, but they were cheap enough I figured it couldn't hurt.