New sensor has been installed. Should have mileage results sometime next week. Engine seems smoother but that could be psychological. I strongly suspect my problem of poor fuel mileage is going to be solved and the problems was, indeed, a sluggish and low output sensor caused by fouling.

What output sensor? Do you meen the O2 sensor?

Yes. should have typed oxygen sensor rather than output sensor.

Lawrence, would you recommend changing out old O2 sensors by default of age/milage even if there doesn't seem to be poor gas milage or outstanding issues? I'm thinking about doing this because I have no record of them not being original.

i wouldn't...
remember the porsche saying - if it ain't broke, STAY THE HELL AWAY FROM IT! :p lol

I would not change it unless mileage drops off. Mine had been in car since 89K when I bought the car. I could not figure out why the mileage had dropped on my car. If I did not have the drop in fuel mileage, I would not have taken it out, tested it, and replaced it when it failed the test. I tend to leave "well enough alone". Jury is still out because I have not used a tank of gas yet, but I rather confident about the fix.

I've read stuff saying the sensor should be changed every 30k miles. But the article was written by Bosch. They have a conflict of interest and would like everyone to change their sensor every 30K.

We had a sedan that we put 140K on before trading it. It's mileage never fell off and I never changed its sensor.

Mileage Results
 

Well I finally got around to doing a mileage test with the new oxygen sensor. I missed my February trip due to snowy weather. The mileage had dropped off from around 28 to under 25 on the standard trip I make to Road Atlanta. Just filled the car and it got a little over 29. It had gotten about 24 around town when I filled. Before the new sensor, it had dropped off to 19 around town.

So, my conclusion is this: the poor mileage was due to a sluggish oxygen sensor. Mine was so bad that I was able to pinpoint the problem with the blowtorch test. Incidentally, propane is a carbon-hydrogen molecule. Its chemical formula is C3H8. Octane is also a carbon-hydrogen molecule, C8H18. Larger but the same basic elements.

Since my mileage is great, I will assume that my O2 sensor is still OK.

Harvey

Okay, but the fact that you are burning a hydrocarbon is virtually irrelevant. The O2 sensor once heated acts as an oxygen-concentration comparator.


That said, about 80% of the time bad mileage problems are a bad O2 sensor. Good to hear you got your problem fixed :)

I encourage changing them every 4-5 years if there are no mileage problems, sooner if there are. The reason being once they start to go bad, you start to get carbon buildup on piston crowns, etc. Things that can continue to cause problems once you change the O2 sensor.

I'm tickled the mileage returned to where it was. Plugs look really good too. Before, they were sooty.

If you get the Bosch universal one, it costs about 1/2 of what the one with the special connector. It's the same sensor, just no union that plugs in. You have to splice.

The cheapest I found was for a ford, maybe a tempo?...
It was $23CDN for a 3-wire O2 sensor. I had to use my own butt connectors, but that's no big deal. That said, the universal was second-cheapest. And the proper Porsche-fitting one was about 4x more.

Sounds about right for the Ford part. I've used three of em in three different cars and had excellent results.

Do you happen to recall the part number?... Because I don't.
I used to have a friend that worked on the store, so he just brought up like 100 of them and scanned them all until we found the cheapest, I don't think anybody else there would do it, lol.

Bosch part number 13913. Universal type 3-wire. $34.99 on sale at Advance Auto Parts.

Is the universal for any car or specific?

For any car that takes a 3-wire sensor.

Does anybody know the ford part number?