I have 158k and mine are still original. In my opinion, O2's are a "if it ain't broke don't fix it". As long as it's getting expected gas mileage, runs well, and no DTC's I'd leave them alone.

 

I thought that way too, but a couple of yrs back. We move back to southern ont. My wifes truck failed the etest it needed. Found out it was a weak o2. I have to get mine dont, so I thought play it safe.

 

I think they loose efficiency. I replace mine at 100k.

 

Hmm - my truck has never gotten better gas mileage.

 

I replace my front O2's with Motorcraft every 35k or so with forced induction. I would replace then every 50k without FI, they do at least 95% of the fueling work for the average driver.
http://www.vmptuning.com/forum/showt...ighlight=bosch

 

Also the ceramic starts to chip off. Its like a ceramic bowl, after it heats up a few times, it expands and starts to crack. The wires get crap more resistance, etc.
Well Im going to order some Motorcraft ones. And try them. Ill use these in the downstream. since they really doin do anything.

 

I don't want to change my O2 sensors and something happens... I have a 1800 mile round trip coming up.

 

Could this be caused by the O2 sensors never being changed??
'98 F150 4x4 with a 5.4 and has 170,000+ miles on it.
I was thinking of changing them, performance has not been compromised. Truck still runs good and pulls my dump trailer around with 3 - 4 tons of lumber or firewood on it with no problem.
I know my fuel mileage is down a little but with all the towing of different stuff I never really keep up with it.

How many sensors are on this engine??

Thanx, Doug

 

The CEL is on? You need to get the codes read.

 

My truck has 147k miles on it and was running rough with low power, so I decided to change the O2 sensors this weekend.

However now that the job is complete it is throwing two codes, p1055 and p1035, both related to the heating of the O2 sensor. The codes are not continuous. I can reset them and then drive for miles before they come on again.

I used new Bosch sensors.

Any ideas why it would throw the codes?

Thanks.

 

You didnt plug them in all the way. check your connections.

 

I double checked the connections and I think they are tight.

Any other suggestions?

Thank you for the help!

 

Yea, Bosch are factory original sensors for most 97-03's. Tuners don't like them all that much because they're flaky on the graph. Motorcrafts, -smooth, steady and consistent,- graphed.

Which is better ? I would guess the Motortcraft, but that's just a guess. Bosch may be buggy on the graph, but that's as far as it goes. There's no data either way.

Any of those two O2 sensor brands will keep her running right.

I wouldn't stray from the above. I tried Borg Warners once. I went down to 9 mpg with that junk. Swapped back pronto lol. It seemed to run okay, -just pigged the fuel.

 

Yea, check your connections. "I think they are tight" don't get it lol.

I finger print can goof those up. Sensitive inside those connectors and easily contaminated once disconnected.

So yea, check your connections, -don't just blow it off.

 

Changed over to MCs, havin't seen a big differance. Maybe runs smoother.