hi,
Can you help me disconnect the front O2 sensor from its wiring harness? Apparently there is a locking plastic tab, but I cannot see the connector close enough, or at the right angle, to see how this locking tab works, so I don't know where/how to push/press it so that I can disconnect the sensor.

My other question is this: I had a mechanic replace this O2 sensor in September 2020, with an Amrxuts O2 sensor, which was about $64 on amazon:

Amrxuts 234-9017 Upstream Sensor 1 Air Fuel Ratio Oxygen Sensor for Honda 2004-2005 Civic EX Acura EL 1.7L l4 192400-1170 36531-PLR-003

Ever since the replacement, every ~two months the Check Engine light comes on again - still - and I have code P0134 "O2 sensor circuit". I can make this go away by pushing/squeezing the wiring harness that connects the sensor cable to the cable coming out of the computer/engine/car, and then clearing the OBD-II code. This tells me that this cheap sensor is not itself faulty, but perhaps the problem is just a loose, flaky, or dirty connector? My plan is to disconnect the sensor and inspect/clean the contacts. Thoughts?

thanks,
js.

 

push the unseen tab with a small flat blade screwdriver (our fingers are too larger to push on that small area), it is on the left side of the metal holder which keep the electrical connector from being loose

I can post a pict later...

As for O2 sensor... the OEM are better quality, we installed the denso. This is on a 2005 civic with the 1.7L. These connectors are fairly tight... even in our oil leaking valve cover spewing oil a bit everywhere...

How many miles on that engine?

 

Thank you Michel - I do think a pic would help - I can barely see anything down there - can't see the side of the plug with the tab. Here's a photo showing what I *can* see.
The engine has about 100,000 miles on it. (Replaced timing belt, water pump, tensioners, belts and spark plugs at 14 years and 95,265 miles, which was two years ago - a service shop did it for me.)

Honda dealership wants $1000 to replace this front O2 sensor ($600 part, $400 labor), but at this point, I'm not even convinced the problem is inside the O2 sensor itself. I mean, if it's a flaky wiring harness connection, maybe Honda's $1000 job will have the same problem. So far, every time I get the Check Engine light and the P0134 code, it goes away for at least several weeks (or months) after I just push the wiring harness halves together. I'd have no problem paying Honda, if I were 100% sure their overpriced work would fix this problem, but now I'm not so sure.

But yes, if I could go back to last September, when I bought the O2 sensor, yes I'd buy the $420 Honda OEM part.

 

You can see the tab to press in this video:

 

great some people are faster, but here is my take, where I slide a small screwdriver against the tab




I paid $180ish for the good denso sensor, it comes with the antiseize compound, the socket is inexpensive

I have both sensors mounted on the same metal tang, the pre and the post

 

Thank you both - very helpful.

The P0134 code hasn't come back since I just pushed on the harness/connector - it's been about three weeks - but I expect the code to return, then I'll try to unseat and inspect the connector, with your guidance.

Very interesting how the video that tech8 posted says this is not really an oxygen sensor - it's a [much more expensive] air/fuel ratio sensor.