Oxygen sensors?

[mtnrgr]

The two oxygen sensors on my 94, are they both upstream or downstream? What is the better brand to use? I know Bosch are the ones ford uses back then. I can buy them for 20.00 each on ebay, and there are others for 15.00 each. Dealer and parts store way to much. Should I use Bosch or will no name brands be as good?

When I replaced them, not sure how many years or miles ago. I did buy Bosch sensors.

 

[RonD]

Bosch are usually best to use

In a 1994 V6 Ranger just the 2 upstream O2s

Downstream were added in 1995 Rangers when they got the newer EEC-V computers

Do them one at a time so you don't reverse the left and right side plug ins

 

[Roert42]

I think they normally last 100,000 or 150,000 miles before they wear out. At that rate, I would go with the OEM brand since it's not like you have to do it every couple of months.

 

[SenorNoob]

Check with RockAuto. I got a Motorcraft a few years ago for only $20.

I just looked. Motorcraft is $74 now. But Bosch is only $24

 

[Chapap]

When I changed mine, I read on some other forum that Bosch is going down hill and NTK is a better choice. I believe OEM is NTK or at least has the same physical look.

 

[mtnrgr]

I found a seller online selling brand new ford sensors for 50.00 for a pair. I bought those, and installed them today. They only have ford and the part number stamped on them.

 

[mtnrgr]

Have a couple of questions about cat converters and oxygen sensors. I found that I replaced the oxygen sensors back in 2009, roughly 150,000 miles ago. I had new walker cats put on around 3 years ago, they have about 50,000 miles on them now. Last year when I had my truck smogged they had around 40,000 miles...truck passed my mechanic friend said that cats are getting weak. Could the oxygen sensors have caused this with them being that old and miles?

Since I changed them my ranger runs alot smoother, and always used Chevron or shell mid grade gas. Now that I installed these new o2 sensors will this make the cats better or will they continue to go bad?

 

[RonD]

O2s are the only sensors that wear out
They use a Chemical to detect Oxygen in the exhaust, and they simply run out of that chemical
100k miles or 12 years, which ever comes first, after that your engine will run Richer and Richer until it finally sets a code, and that extra fuel you were burning costs at least 5 times as much as O2 sensors, lol, with todays prices, 10 times more

The extra, un-needed, fuel also makes the Cats run hotter than needed, so will wear them out faster

O2s generate their own voltage, under 1 volt
0.1v is high oxygen which most call Lean, but this is exhaust not fuel mix
0.9v is low oxygen, called Rich

O2s can't read oxygen levels until they are heated up above 600degF so most are "heated O2s", so they can warm up faster

Computer has no comparison sensor for O2s, so they are "The word of God" as far as computer is concerned
Newer O2 will run at about 0.45volt, if fuel mix is correct
As they run out of chemicals the voltage drops, very very slowly, so "shows leaner" exhaust even though it IS NOT
So to keep the O2s at 0.45v the computer adds a little bit more fuel, cats run hotter
And so it goes, cash out of pocket

So changing O2s every 100k miles or 12 years means they are better than FREE, you saved 9 times the cost in wasted fuel

 

[mtnrgr]

Impressive as always Ron, how do you know all this? Your a really smart man. Was hoping you would answer this one.

Didn't ever got a code from those, I replaced them due to miles and years. In the last few years as they were really past thier point of needing replaced. I was told by Jack my mechanic friend, and noticed that my tuck was running a little bit rich. Always thought it was just how the truck was running from how I have built the engine back in 2017. Now these new pair of o2 sensors have been on there a few hundred miles now..truck runs quite a lot better.

Now the cats are cooler with these new o2 sensors..they are Motorcraft sensors that only have ford and the part number stamped on them. The cats won't fail will they, do you think they will pass smog a year from now?

 

[RonD]

No crystal ball here but, Yes, they should last

Cat converters are only rated for 100k miles, most are warrantied 80k/8 years, but generally last 300k if there are no engine issues, i.e. rich running, oil burning, coolant burning(head gaskets), any can shorten Cat life