O2 sensor kaput - which replacement?

[csown]

Hi All,

My CEL went on about a month ago and the gas cap trick didn't work this time. I just got delivery of an ODB-II reader and read out the codes. I have 1166 and 1167 which looks like the heater element of my O2 sensor is dead and the sensor will need replacing.

My question to you on this forum is whether I need to get a special sensor or not. My Insight is an '02 CVT and my understanding is that it doesn't do the lean burn thing like the manual Insight does when cruising at low revs. In that case, I am guessing I wouldn't need one that detects a wide mixture range, and therefore any old 4-wire sensor would work. Is that correct?

I have seen some Bosch and Denso sensors for $250, unbranded (and potentially used) for $28, and a new Denso sensor on eBay for $100. How do I tell if the sensor is a wide ratio range sensor? Is there a special name for it?

These are the ones I've been looking at:
cheap
eBay
not-so-cheap

Also, I just want to make sure that this code refers to the upstream (pre- catalytic converter) sensor and not the downstream one.

I'm pretty new to car stuff but I'm having lots of fun doing this stuff myself. I hope a good spanner and my skinny biceps will be enough; I heard you need a long lever arm to get O2 sensors out.

Thanks in advance for any help!

-Chris

[BillR]

I seem to remember reading somewhere that Honda had to design an O2 sensor specifically for the Insight because regular sensors just weren't accurate enough. It could be that time has marched on and now there are other manufacturers building sensors that will work.

When mine gave out 4 years ago, I replaced it with a Honda part. I don't remember it costing $400. I'd have to check my bills but I thought it was around $250 Canadian and just under $200 US at the time. Have the prices gone up?

If it's the top(first) sensor, it's easy to get to and I used (of all things) a crescent wrench (metric of course) to take out the old one and put in the new.

Let us know how what you bought and how it works.

Bill

[Willie Williford]

The CVT takes a std. 4 wire o2 sensor. The codes you read refer to the #1 sensor. (First, or primary) The "lean burn" sensor for a 5 speed is 5 wires.
A 22mm end wrench will remove it easily. The box end will not fit over the connector.
There are things that I would do first before replaceing the o2 sensor.

Willie

[Insightful Trekker]

Hi Willie!

Just a friendly FYI ie 5 speed Insight _primary_ (before the CAT) O2 seneors:

00-01 (parital 01 model year). Yes the "old" style 5 wire LAF type primary O2 sensor was used. In mid production 01 and _all_ later model year 5 speeds the 5 wire type sensor was "modified" to use 4 wires, but its still an uncommon and expensive LAF type.

Beware trying to "make" a conventional 4 wire sensor work in substution. It won't, and will likely cause catalytic converter damage.


AFAIK (and I checked my sources today) LAF type O2 sensors are still shockingly expensive

HTH!

[revinger]

I had the primary(5 wire) O2 sensor at about 110,000 or so about 2 years ago. The sensor is made by Bosch. I dont remember the exact prices but priced it through Hondak, Autozone and Napa. Napa was the lowest price and while not cheap I remember it being more than 100 less than what Honda was asking for it at the time.

[csown]

Hi again,

Thanks for the replies so far. They have been very helpful, and I wanted to give an update.

So I figured the cheapest sensor, a universal heated sensor (link) was worth a try so I got it, spliced it into the harness, and put it in.

After I cleared the previous codes, P1166 and 1167 (Primary HO2S (No. 1) Heater System and System Electrical) are now replaced by P1162 (Primary HO2S (No. 1) Circuit Malfunction).

I pulled out the new sensor to double-check wiring. Even with the signal / ground wires flipped around it still triggers CEL. Next I checked the sensor on the bench with a torch. It gives 0 V at room temp, 1 V when hot, and cools to about 100 mV quite rapidly. The new sensor appears to be good. Nevertheless, my ODB-II reader is reading back 0 V on O2 sensor 1 and only 15-35 mV on O2 sensor 2 (I assume this is the downstream one).

This brings up two questions:

1) Have I picked the wrong sensor? I saw a related post (link) that seemed to indicate that a universal type is the wrong one. Other than the 5-wire LAF type, which is used in the MT Insight only, are there other types of sensors that give significantly different voltage outputs? The old sensor only gives about 50 mV when heated with a torch; I am assuming it's broken.

2) Is this a bigger problem than just the sensor? If the ECU isn't reading anything, it's possible that the signal or ground wire is broken elsewhere or the A/D for sensor 1 inside the ECU is broken. Any tips on troubleshooting this?

For what it's worth, the old broken sensor has the following markings:

DU2
DENSO
192400-1050
10C12


Any further help or comments are appreciated!

Thanks,

Chris


P.S. - Willie, what are the 'other things' you would do first before replacing the sensor?

[Insightful Trekker]

Originally Posted by csown

Have I picked the wrong sensor?

YES

See my reply above

[csown]

Originally Posted by Insightful Trekker

YES

See my reply above

InsightfulTrekker: Please note that I have a CVT model. I thought your assertion above is that a 5-wire special LAF sensor applied only to 5-speed manual model.

I was under the impression that the CVT does not use a LAF sensor, just a conventional one, for both upstream and downstream sensors. The difference being that the LAF sensor measures lean mixtures as well as stoichiometric whereas the conventional sensor only measures a narrow band around stoichiometric. Am I mistaken, and/or misunderstanding something?

Thanks,

Chris

[csown]

Also, can you explain why the new (incorrect) sensor reads back 0.0V rather than between 100 mV and 1 V? The heater appears to be working, and revving at 3K for a few minutes to heat things up changes nothing.

Thanks,
Chris

[Insightful Trekker]

Sorry my bad. It wasn't clear to me that you were a CVT in my first quick read through.

Not being a CVT owner myself I don't have the information on hand, nor do my usual online sources. But neither am I sure that a CVT's primary O2 sensor is not an LAF type. The FSM & ETM do not show a difference (but they do show the 01 and back difference). Even the "official" Honda parts eStore dosen't allow a CVT option to be selected pre the 03 model year. Nor does it give the PN for ready compairson. But price wise its in the LAF catagory on all my online soruces..

A quick call to your local Honda dealer parts counter should be able to clear-up the possible confusion. i.e is there a PN difference for the same model year(s) MT vs. CVT for the primary O2 sensor?

Sorry but online discussions of the intricacies of O2 sensor testing is not my idea of fun. Its complex and requires advanced tools and skills. There have been a few in depth threads on such in here in the past, but you'll probably have a hard time searching them out, sorry.

"Torch" testing of O2 sensors is not standard and fraught with perils. Do so at your own risk!

The simpiler approach is to find out if LAF is required or not. Then the rest _may_ not matter in your case.

HTH!