94 Civic VX Check Engine - O2 Sensor
 

I have a 94 civic VX (non-CA).

It's had the warning light on for a while. Shop said it was a faulty O2 sensor.

Think I've found one here at Autozone.

Before I spend all of that money, I'd love to be confident that this is in fact the problem. Found the thread on the sensor at O2 Sensor Thread

Seems like testing is pretty daunting - particularly, if I read it right, injecting propane to test the rich burn? Should I order the part and just see if it deals with things (seems I can return it to autozone).

Other than the warning light, the only symptom I'm experiencing is an occasional power drop that I experienced long ago with a 78 Toyota with a bad fuel filter.

On other fronts, like everyone, I have rust on the rear quarters. If I buy the replacement panels (see thread), and don't have the tools/skills, do I just find a body shop to do the install/painting? Anyone have suggestions for such in the DC/MD area?

Any info would be much appreciated.

Thanks,
Tim

Hi Tim,
If I was going to replace the sensor for $334 from Autozone I think I just belly up an additional $2.63 and by the Honda OEM o2 LAF sensor direct from Majestic Honda for $336.63.

https://www.hondaautomotiveparts.com/...NIFOLD+%281%29


My sensor has ~100k miles on it and I believe that its output is fading though there is no CEL. I say this because I've run the engine with it disconnected and it is much more powerful and better running throughout the entire rpm range, though the gas mileage dropped by 6 mpg on that half tank.

I bought a Bosch 13246 sensor on ebay and am having problems as it does throw the CEL, the old one does not. I am working with the tech service to review the wiring.

What's up with the pricing
 

So as recommended, I've looked on ebay.

However, I'm suspicious of getting taken - seems like best prices are in the 300s (new, via "real" suppliers). So is there any possibility that these ebay ones for $100 - 250 are legit?

I see a few and wonder if anyone has any experience:

Walker Sensor from Mac Auto Parts and Accessories - $162

NGK-NTK Sensor from the JACP's garage - $250

"Brand new OEM" from Auto Parts Direct to You - $99

All of these seem to be the correct 5 wire item, but beyond that, I have no way of judging...

For this vital engine part on the d15z1, I would just go with the Honda part to safe yourself from the hassle and poorly running car if one from ebay isn't right.

what happens to o2 sensors from old VXes that get retired?

Seems like an obvious place to start, but given the small number of junkyards around here and the small percentage of vx's in the general population, I'm not optimistic...

Walker for $162 should work. I've paid around that for my O2 sensor off ebay and it worked fine.

Low voltage?
 

So I decided that before spending the money for the 02 sensor, I would confirm that was the issue.

I did the CEL test and got code 41 - check O2 sensor heater. I have a manual that says to check the voltage between black and yellow-black on the connector. I did this and I only get 6 volts! I'm wondering if this is my real issue.

Has anyone run into this?

Can I just feed it new power?

Thanks for any thoughts.

- Tim

Re: Low voltage?
 

So has anyone checked to see if you really are supposed to have "battery voltage" between these two wires? I have the same problem.

Re: 94 Civic VX Check Engine - O2 Sensor
 

I did not have a CEL light but was testing the sensor one day and there was no voltage at the wires in question. New 02 produced the same result (of course since it's the car side that was the problem). Lean burn function seems to work just dandy as do other systems. I think the 12v being there would help warm up the 02 quicker as that is it's job. However, I suspect there's only a minor change in efficiency with it not working.
B