derekd

i need to change the oxygen sensor in a 97 ford expedition, is it a
diffucult job or should i let a garage do it

1. Which one?
2. What has prompted you to change an O2 sensor?

derekd

i think they said bank1,and its because my check engine light came on

lugnut

Are you sure you are not just shooting the messenger instead
of attacking the problem?? The sensor is supposed to give
error messages when things are out of kilter. What is the
exact code that was stored? If the sensor is accusing
something in the system of being out of range, the first
thing you do is consider what may cause that and address
that problem. O2 sensors these days are expensive enough to
almost cove a diagnostic fee to be sure you are
repairing/replacing the correct parts.

Lugnut

derekd

i dont know what the code was i brought the truck to a garage and they
said it was the oxygen sensor.what else could it be

lugnut

There are many things that can result in an out of range O2
sensor reading. A qualified techwith a good scanner can
check other calues in the system that may indicate a problem
other than the sensor. As I said, the sensor is just the
messenger in most cases. Many less than qualified techs get
a bad reading on a sensor and immediately replace the sensor
just to find out the sensor was telling the truth. That is
why the exact code and an understanding of what may cause
that code to be set is important. You may need to ask the a
few questions to learn why they condemned the sensor. The
sensor may be the problem - I just want to point out that
several other things can result in a bad sensor reading.

Lugnut

I wonder how many good O2 sensors have been replaced because of a
vacuum leak.

lugnut

Enough to retire both of us very nicely

Lugnut

jim warman

No, no, no.....

Here's how it is "supposed" to work.... We go to whatever auto parts store
that offers free "code scans" (free code scans are, too often, a lot like
having sex without a partner)... The young fellow running the scanner (he
took his McDonalds uniform back at the beginning of the week - now he has a
regular job, he doesn't need it, any more) reads the screen.... Thankfully,
the name of a component scrolls across the screen - at least it's not one of
those pesky codes that requires thought....

It said <mumble mumble> oxygen sensor <mumble mumble>.... That'll be $120,
please. Of course that will rarely cure the problem and we can soon run out
of money trying some of our"experts" other suggestions (he must be an
expert.... only an expert can afford to do this for free)..... just like the
guy on the radio show....

So, this guy finally drops all of his hard earned on "dime store
diagnostics" and, now he needs to come to me..... But, I'm an asshole and a
thief because I need to get paid... the tool monger is after my tool
payment, the kid needs shoes and the wife....for some strange reason she
tells me she can't make supper if there's nothing in the fridge....

Anyway, this guy dropped his whole wad on "maybe it's...." and now he has no
money to pay me.... 500 or a 1000 bucks worth of parts didn't fix it, so now
I should be able to do it for the price of a case of beer since there's all
these new parts in there....

I can come up with several conclusions but the one that sticks out the most
(near like wedding prick).... free - ain't.

DTCs can be either a symptom or a cause.... more often than not, a
symptom..... If it was that easy, I'd be unemployed....

<snip>

Yeah, between the dime store diagnosis and the professional rates,
whatever time and money I invest in tools and knowledge maintaining my
"fleet" is time and money well spent in my book. Nothing against the
pros of course, just so happens I like working on them. Helps me deal
with the service writers too when I do have to go to the dealer, in the
past couple years I've been able to politely suggest the diagnosis up
front. Now for an O2 sensor code I'd try and figure out why its
running rich or lean first.