Will an economy O2 sensor work in my '92 VX, or must I buy a $300+ O2 sensor?

I just ordered one for only $60.71 from the big internet parts dealer, but after reading old threads here, I cancelled it (I hope in time).

Here is the part description on the vendor's web site:

ULTRA-POWER 2345052 {#25025055, 36531P2MA02, 36532PZDA01} (Economy) Info
UPSTREAM; VX

 

Nope, you have to get the high dollar one.

 

Fair enough. How can I verify a particular example will work? What's the lowest price I can reasonably hope to find?

 

5 wires.

 

CA or Federal? NTK 24300 sensor only. Everything else will not allow for lean burn and eventually throw a CEL.

 

Not sure what you're asking.

I live in Washoe County, NV which requires an annual smog test.

I've owned this '92 Civic VX for over 10 years, and it has always shown a CEL 48 the whole time, yet the car has always passed a smog test. Now it has failed smog test even after changing oil, fresh spark plugs, and getting it good and hot on the highway just prior to the test..

So, to simplify, I don't (and neither does the county) care about the CEL 48 specifically. I only seek to lower the High Speed CO and High Speed HC values below threshold. The engine has 250k miles on it so there's no guarantees, but it doesn't smoke at all, runs fantastic, and gets 40 mpg around town.

My mechanic said I should replace the LAF, clean out the intake plenum, and run a bottle of CataClean through the system.

Thanks for the specs on the LAF. Any additional comments will be appreciated!
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Thanks. I just ordered an NTK 24300 from R.A..
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Federal or CA emissions. A CA emissions car does not use the 5 wire wire sensor and will not do lean burn.

Cleaning the EGR passages in the intake manifold is highly recommended but it is no easy task as they are welded shut. There are a few write ups around here on the process. I removed the welds, cleaned the passages and then capped it back off with 1/4 inch pipe plugs for future servicing.

48 is a LAF error, new sensor should resolve that and bring your MPGs up. However be ready for the new found lean burn mode. The throttle pedal goes into what can best be described as a dead pedal mode. More input does not increase power as expected until you break the load threshold to get out of lean burn and then power returns to normal. After you get a feel for it you can sustain lean burn fairly easy and get great MPGs.

 

Thanks. Yeah, I've read up on the EGR passages, not going there. The mechanic pointed to the large upstream runner connected to the air cleaner hose, not sure cleaning that will make much difference.

On the LAF, I could put in the new one and hope it helps me pass smog. Then I could put the old one back on for driveability. I've never experienced the dead pedal mode, yet the car still gets better than revised EPA estimate around town, and is very responsive to pedal inputs.

As an aside, this county will issue a smog waiver if I can produce emission system parts+labor receipts in excess on $200, purchased after the first failed smog test and before a second failed test. I do have to take the car to DMV for inspection (for modifications and/or visible smoke) but otherwise I should be good for a waiver after purchasing the LAF. So the high purchase price of the 5-wire LAF actually works somewhat in my favor, there should be no question about the applicability of the part to emissions control.

Incidentally, looking ahead, how does that 5-wire LAF harness connector disengage? As usual, it's not obvious to this casual observer. Do the Japanese get a kick out of designing puzzles? ;-)
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Ooh,. I forgot about this. The ca version uses a 4 wire o2 I think

 

Off the top of my head, there is a latch that pulls away from the little mounting tab that holds the plug out in space. Then press the other latch inward to separate the plug halves. Sometimes pushing the plug tighter together before pulling it apart breaks the seal of being stuck together for 30 years.

 

Thanks. I got it apart, but as usual it seems more diabolical than necessary. Almost as if Japanese law mandates child-proof connectors.
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Update:

I got the $200 NTK 5-wire LAF from RockAuto. Had to have my mechanic bust the old one loose with his special crow-foot wrench and, frankly, muscles. Put the new O2 in and it drives noticeably better, and now my CEL doesn't come on at all! Since I bought the car it has signaled 12 (EGR) and 48 (O2) but apparently the bad LAF was also causing the EGR error. (We'll see how long the CEL stays quiet.)

Now I have the $30 CataClean in the gas tank (w/ ~4 gallons gas remaining, per instructions) and I'll drive it 20 miles or so this weekend then put fresh gas in the tank.

Then the 3rd Smog test. If it fails, I've now got the minimum $200 in emissions parts receipts for DMV.

 

Awesome! The VX is hypersensitive about that LAF being correct.

 

But - I was still getting 40 mpg around town all the while (on summer formula). Adjusted EPA estimate was 39 city / 49 highway. My engine has 250k miles on it. And I live at 4700 ft ASL, so ... less oxygen, less power, lower mileage. Go figure. Let's see what I get going forward. I wish I'd replaced the LAF years ago, even if it was passing smog tests and running well.

 

Update 2: I had to drive about 30 miles in near 100f heat yesterday, and then I did get CEL codes 12 and 48. However after replacing the LAF I had not reset the ECU, so one of those codes could be stale now. Since removing the BACKUP fuse to clear codes, I have not yet seen a CEL, so I'll have to wait, but I'm hoping the 48 is now absent. It makes sense that changing LAF would not really cure the 12 EGR issue.
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Update: The NTK upstream sensor worked to pass the SMOG test.

Looking ahead, I went to RockAuto to order another one for next summer's renewal, but find the NTK 24300 price is now $223 (last summer it was $87).

Does anyone know where I can source an NTK 24300 (for VX only) for < $100?

Brian