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I failed smog. Heated O2 wiring questions now.

Keitha said:
Looks like you have it wired up and good. The signal wire (odd color) is the only important one to have correct. With the other 2 wires that should be the same color, one goes to 12v, the other to ground.

Regarding your question: If you are only remote starting your motor to warm up, then you are OK with this. The O2 sensor may not function at this time w/o the 12v source, but your motor should just run in open loop until you actually turn your key.
I wired mine through a relay triggered by my fuel pump source. This way it is not constantly on if I have my key on / motor off.
Click to expand...

Based my wiring off the picture of that grand national plug.

Didn't think of key on - motor off.....but i really don't see that condition ever. I've got a separate switch to run my radio on w/o key, so can't think of a situation that i'd have the key on.

So, does the 3 wire o2 work without power? Will it work, unheated, like my old one......or not at all?
 
I know this is way past the point of taking it off, but...

I just smogged my '89 on Saturday. Smog guy didn't care about the throttle body spacer (with no CARB sticker whatsoever), nor did he care about the salad bowl, both of which I was expecting to hear something about...

Sorry to hear about all of your troubles though, looks like in your area they want to see even less NOx than where I live (and I thought they were stringent here!), in which case I would have failed there too.

Last I heard, by the way, was the PO box trick may not work anymore. But if you have a buddy who lives in a non-smog area... it's highly recommended to register there. But I think you still have to get it to pass this time first anyway :dunno:
 
munepit said:
Im glad you didnt have any problems! Right on!
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Good news for us all, but i'm guessing it has to do with how educated your guy is.

I painted my spacer the last time i had it out, just to try and avoid the discussion....
 
Looking over your thread, I find a few numbers very odd appearing compared to my recent smog experience.

I'll spell out what my sheet says in regards to the tailpipe output:

15 mph: 1461 rpm
25 mph: 1418 rpm

%CO2:
15 mph: 13.7
25 mph: 13.7

%O2:
15 mph: 1.4
25 mph: 1.4

HC
15 mph: MAX 110 AVE 61 MEAS 79
25 mph: MAX 90 AVE 47 MEAS 60

CO
15 mph: MAX .58 AVE .15 MEAS .24
25 mph: MAX .54 AVE .16 MEAS .16

NO
15 mph: MAX 970 AVE 420 MEAS 965
25 mph: MAX 581 AVE 332 MEAS 579

I find it interesting that even though I'm a "High Emitter Profile" my max numbers are higher. I wonder if my EGR started working at 25 mph, considering the rpm wasn't that much different (but my speedo is about 10 mph off).

In any case, good luck... I hope you get to pass soon!
 
I found out my ERG is not working. It won't hold a vacuum. Installing a new one today. Hope that helps.
 
A bad EGR prevented me from passing smog last time too. New one and I got by just fine.
 
Installed a new EGR. The one I took off was toast. Waiting on the pigtail I ordered comming too. I have the heated O2 waiting to go in. Im just going to wait till it shows up in the mail and install it before smogging again. Just in case.

Took it for a test drive. Need to do some cutting.









Thanks for all the help guys! Really appreciate it!


2012-06-28_17-45-50_228.jpg




2012-06-28_17-47-09_607.jpg
 
I realize that you are talking about cutting fenders, but the proximity of your talking about an O2 sensor and cutting made me remember.

Make sure you do not alter the wires on the O2 sensor.
Most of them used to, and I think still do, get their oxygen reference through the wires around the insulation.
Friend of mine replaced his when the wire got snagged and torn off.
He just spiced in the new one since his old plug was destroyed too.

It didn't work.
He took it back and got a new one.
It didn't work either.
I wandered in just as he was about to cut the connector off the third one.

I pointed out to him that if cut that connector off, spiced the wires and put some heat shrink on, the sensor could not detect the outside air.........

He found a connector in the junkyard and spliced that side.
It was about two weeks later, when he was feeling good with a couple of beers, he admitted to me that he had screwed up the first two.......
 
munepit said:
Installed a new EGR. The one I took off was toast. Waiting on the pigtail I ordered comming too. I have the heated O2 waiting to go in. Im just going to wait till it shows up in the mail and install it before smogging again. Just in case.
Click to expand...


Towed up to tahoe yesterday, and the truck ran better at WOT than it ever has.

That heated O2 really made a difference. I cut/spliced my o2 wire into the new plug, haven't had any issues or codes.

Hope yours goes well!
 
And to answer the question, yes the heated O2 will work without the heater wires connected, as long as the exhaust stream is hot enough, which is why heated O2's were invented.

A fair number of the "early" GM EFI/CCC setups went open loop at idle because the sensor didn't stay hot enough. Mine normally goes open loop at idle, but any amount of throttle brings it back to closed loop.
 
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I got that plug adapter yesterday. Need to install the O2 and adapter and switch tires. I went to the smog shop and the 42s wont fit on the machine. Putting on the 38s.
 
munepit said:
I got that plug adapter yesterday. Need to install the O2 and adapter and switch tires. I went to the smog shop and the 42s wont fit on the machine. Putting on the 38s.
Click to expand...

Switch wires? I'm guessing you mean power wires?
 
Ok, I'm installing the heated O2. The plug is wrong on the pigtail. It's male and I need female. I know Fordum said not to spice the single O2 wire but what do I do? Thanks,



Here is the pigtail.


2012-07-13_19-56-41_688.jpg


The O2 wire from the one I just took off.

2012-07-13_19-56-58_35.jpg
 
Well, you just caught me as I was headed to bed. Going fishing tomorrow and have to get up early.
The last time I checked, O2 sensors got their oxygen reference through the main wire. In other words, the air seeped in along the wires inside the insulation.
What the idea for this was, I have no idea.
Maybe it was just an easy way to keep water and crud out of the sensor.

I suppose the wire could be spliced as long as the insulation was not sealed off from the air.
In other words, don't use heat shrink tubing in general, and especially not the type with the glue inside.

If you cannot find any other way, I would suggest that you cut off the connector, splice the wire, and leave a tiny bit of bare wire on the O2 sensor side. Just a gap big enough for air to get in.

Its possible that they have changed the method by now, but the last time I heard of someone messing up by splicing was about a year ago.

Of course there are many different types out there now, and a couple that do not require an outside reference.

Just to be on the safe side, I'd leave a gap.
You might look where the wire is terminated now, to see if the insulation is sealed or not.
 
For what It's worth, spliced mine and it worked perfectly. And (no offence good fordum) but i do believe the wire seeping oxygen thing is an old wives tale. Just Google how an oxygen sensor works. Iirc It's this crazy thing where pores open up on the tip and allow the oxygen to "enter". Bagh, now I must go searching!
 
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