Please Help! 1986 CRX HF & CA Smog

[skypig]

I acquired a 1986 CRX HF that’s in great shape and runs really well. It has no rust, the frame is straight, all of the vacuum hoses (lots and lots of them) are in great shape, and it is all original as far as I can tell. It has the federal emissions (KA) carbureted setup. I’m trying to restore this vehicle to use as a gas saving commuter and it needs to pass California smog (enter your sympathy noises here). I took it in for an initial smog test to see where it stood. Well, it failed miserably with high NOX (as in gross polluter). I’ve started troubleshooting and find that I need an oxygen sensor; the 5 wire, impossible to find one, with a Honda part number of 36531-PE1-A02. Apparently this is a wideband sensor. I’m not seeing any voltage change when I connect to the white wire and disconnect vacuum lines to cause the engine to change its air ratio.
I have read a bunch of on line forums regarding this part and the difficulty of finding it. Most of these threads seem to date back around 2008 – 2010. I am hoping that there has been some new information or some folks have found a way around this dilemma. If someone knows where I can get one of these babies I would really appreciate it.
Otherwise, can anyone offer a workaround or substitute to enable this to pass California smog? I see a lot of information regarding the later VX model, and the L1H1 O2 sensor. Has anyone tried using this, or another O2 sensor in the 5 wire 1986 CRX HF and gotten it to work correctly, and more importantly, to pass CA smog? Can one of the wideband controller kits be used to get around this issue? If so, how is this set up? I have found where some owners have swapped out the ECU from the CA to federal model with the intention of getting the lean burn feature. Would it be plug and play to go the opposite route and use the CA ECU and a four wire O2 sensor?
I'm hoping some of you modder gurus can give me a direction to go with this. I really want to get this car running and would appreciate any ideas.

Thanx, Biff

[AndrzejM]

I was looking for your part number and it seems that it's not a wideband O2 sensor. I've found information that it's a simple universal lambda sensor.
I've found it for 25$ here: 36531-PE1-A02

[skypig]

What did you find to make you think it is a narrowband sensor? I have not found anything completely definitive but the information I have gleaned off of the forums is that it is a wideband sensor. If it's not, I may have an easier time working around the issue.

I saw that site this morning, and even considered buying one just on the off chance that it is compatible, but you must buy 10 minimum of the item. Also, the picture shows a one wire O2 sensor, and with all of the compatible vehicles and o2 sensors that it shows, I don't believe they are really the same sensor. From all of the research that I have been doing it looks like this is supposed to be a wideband sensor. I'm not sure what the voltage readings are supposed to be but mine started at about .5 volts and went up to and stayed about 1.2 after the vehicle warmed up. There was no change when I opened up a vacuum line and caused the engine to slow (or even stop as I removed a large vacuum line). It also rattles when out of the vehicle and is shaken.

[some_other_dave]

The folks over at Portal - Red Pepper Racing know a lot about 1st-gen CRXes and the Civics they share a platform with.

Five-wire sure sounds like a WB O2 sensor, but I didn't think those were available in 1986? Though I must say my own interest was in the 88-91 Civic platform, not really the earlier ones.

-soD

[skypig]

Thanx S_O_Dave. I am waiting for my registration to be validated at RPR so I can post my dilemma there as well. I'm starting to think I should have waited and gotten a model a few years newer with FE.

[arcosine]

Since when does a carburated engine need a o2 sensor? Nox indicates the the engine is running too lean or the igntion timing is advanced. Check the timing and set it to the CA spec and there are no vacuum leaks. I bought a wide band 5 wire sensor for $25 on line.

[skypig]

Please arcosine, tell me where you found a $25.00 5 wire wideband o2 sensor.

As far as having an O2 sensor, I guess it's an emissions and fuel economy thing. Appears that the O2 sensor was used to put the engine into lean burn mode. There is an ECU that the signal goes to and this changes some magical vacuum line to adjust the air into the carb. There are no manual adjustments for air/fuel mixture.

You are right though, it does not need the O2 sensor to run. This car runs really well. I have not had it on the road enough to be able to determine MPG since I cannot legally drive it until I pass smog. But in testing it around the streets and a couple of freeway tests, this thing runs great!

After my first smog check I did find the timing was quite advanced, but I find it hard to believe that just adjusting the timing is going to make enough difference to bring my NOX levels down to California legal standards. I realize I may need to put a cat converter on this as well, but I would rather get it running to specs before I throw that at it to try to get it to pass.

If I need to use a manually controlled wideband O2 controller to get the correct fuel mix, so be it, but I am hoping to get more definitive information from people that have actually dealt with some of these things. This is my first dealing with any type of Honda, and all of my carb experience is either pre ECU and O2 sensor, or small engine applications. There are so many folks here with so much more knowledge than I have so I want to try to take advantage of that and go into this armed and hopefully less dangerous than I already am.

If someone knows how to get it to pass CA smog without the O2 sensor working, I'm all ears.

[user removed]

Are you sure it is a 1986 model. What is the production date? Does the engine number match the original HF engine.
I bought an 84 (7-83 production date) CRX 1.5 brand new in Houston texas. Not the HF model. I thought the 84-86 models did not have a cat, but that is old memory. I know my 1.5 did not have a cat or an 02 sensor
There were a lot of changes in 1987, but I thought the 84-86 models of the 1.5 and the HF, which originally was a 1.3 liter engine, did not have cats. I know mine did not have a cat.
The plethora of vacuum hoses indicates the car is carbureted, mine also had a lot of vacuum hoses and had the prechamber venturi in the carb which ran at around 12 to 1 AF ratio, while the main circuit ran at 18 to 1 AF ratio. It may be that your federal version can not be made to pass California emissions. Is it possible to get a waiver?

regards
Mech

[skypig]

Not being next to the car you make me wonder if it is an 86 and if the engine is correct, but yeah, I'm 99.9% sure its an 86 and the engine is stock. I have looked at the door jam and I think the build date was late 85. I would have to check all that again. But with everything I have done on it I have not run into anything that made me think something was not correct or stock.

In the 85-87 productions dates there are a few different versions, some with an O2 sensor and some without. I ran into a couple this past weekend that did not have an O2 sensor. They did all have a cat though.

I read something about Honda basically disabling the lean burn feature in the federal version that went to CA. This enabled it to pass CA emissions (high NOX). So it should be able to pass... I hope. I have not looked into a waiver yet. If I go that route I will have to take it to a shop to get "official" paperwork stating that it cannot be fixed.

[arcosine]

An 86 should have a cat on it and it will not help the Nox. Retard the timing! Google search for a cheap o2 sensor.