several symptoms, no clue

[myfirstmazda]

no cure yet, but I pulled a code 17(o2 sensor,inversion?) --- by the way, what does inversion mean? I was wondering if there's a way to test the o2 sensor before replacing it. also, the guy at pep boys asked if it was before the cat or after. I don't remember seeing one after. am I missing one or did these only come with one? I'm wondering if I'm having more than one problem, maybe it's the o2 sensor causing the overfueling, and a dirty fuel filter causing the surging.

[Ryan]

http://www.mx-3.com/manuals/showimg.php ... F1-151.gif" onclick="window.open(this.href);return false;

http://www.mx-3.com/manuals/showimg.php ... F1-075.gif" onclick="window.open(this.href);return false;

[myfirstmazda]

cool. those are definitely helpful. thanks.

[MX-3zoom]

o2's aren't exspensive are they, might as well swap it out weather it needs replaced or not.

[myfirstmazda]

yeah, it's only like 17 bucks, but I'd rather not replace something if it's still good.

[myfirstmazda]

so Ryan, you posted a link:
http://www.mx-3.com/manuals/showimg.php" onclick="window.open(this.href);return false; ... F1-075.gif
in which code 17 is the feedback system.
but in this chart I saved off the online manuals, it says code 17 is specifically an o2 sensor inversion:

which one should I believe? I'm not trying to say you're wrong, I'm just confused.

[Ryan]

I may have picked the wrong chart for your year/car. Do whichever matches.

I do remember code 17, I've had it before on my SOHC/BP swap. It should cause the CEL to come on just momentarily. I would replace the O2. I never got that code again after I did that.

[myfirstmazda]

ok, because it did flicker on when the engine was stalling out a couple weeks ago, but never before or since. maybe I should just change it after all. I'll test it, though.

[MX-3zoom]

o2 is exspensive! 60 something for one is what i was told on phone. theres one for down pipe, and one upstream. thers plug n play and wire your self.... shucks!

[myfirstmazda]

I called pep boys the other day to find out if they had one, and they said it was 17 bucks. they did ask if it was before or after the cat, and I said it was before. I don't remember seeing one after. I was wondering if there was one missing or something, but then I just figured maybe it only came with one. I tested it today, and it reads low at idle, so I guess I'm gonna go ahead and change it. we'll see if it helps.

[MX-3zoom]

same here... Tomorrow imma slide under there and weld the exhaust leak as well. but can someone tell me where the 2nd sensor is, I've only seen one(connected to heads).

[myfirstmazda]

mine's right there under the hood. in the manifold, I think.

[nos92mx3]

mine's right there under the hood. in the manifold, I think.

Yours is OBD1 you will only have 1

same here... Tomorrow imma slide under there and weld the exhaust leak as well. but can someone tell me where the 2nd sensor is, I've only seen one(connected to heads).

Yours (talking about the 96 I presume) Is OBDII the 2nd o2 sensor is basically a catalytic converter monitor, so it should be after the 1st converter.

[myfirstmazda]

wait, I read that procedure wrong, my sensor might be ok. I thought it said voltage should be 0.55 at idle, it actually says to run the engine at 3000 rpm in order to get it to read 0.55. mine reads about 0.22 at idle, and about 0.85 at higher rpm

[myfirstmazda]

could this be a timing issue? I'm thinking erratic advance might cause the surging, but what about the overfueling at idle? weak spark? all cylinders are firing, just maybe not as completely as they should.