1992 VX LAF (O2) Sensor Replacement
 

Had problems with rough idle/running and Check Engine light on my '92 VX (166K). Took it the shop: they diagnosed LAF (O2) sensor failure. Said shop wanted to charge me nearly $600 to replace it ($500 for the part, about $90 for the install). I thought these prices were ridiculously high, so to the web I went. I found the OEM part at Majestic Honda for $350 w/shipping.

I now want to install the sensor myself. The shop told me that one must use a "special socket" to install the sensor to avoid damaging the wiring and harness. They also told me that the car's computer must be "reset". For this they want to charge me over $90. In light of this I have a few questions:

1. Is this "special socket" really necessary, or can I just use a box or open end wrench to do the install?

2. Most computers just need a cutoff of their power supply (such as disconnecting the battery) to effect a reboot or "reset". Is this the case with the VX, or is there some special protocol I have to follow?

The Chilton Manual I've got contains nothing whatsoever about LAF or O2 sensor replacement...

Greatly appreciate any helpful responses...

I changed my oxy sensor on my cavalier (quite a while ago) and the "special tool" was a socket with a groove cut into it so the wire could hang free.

I got my "special tool" from autozone (maybe advance auto) for $15 on the loan a tool program and brought it back at which time they refunded my $15 and I was good to go. I am not sure if you can do the loan a tool thing if you don't buy the part from them but it is worth a shot.

the install on my cavalier was really easy. good luck to you.

*edit* it was easier when I had the funny socket. I guess you could do the same thing with an open ended wrench though. I can only speak for my car, not all cars.

Does your CEL stay on all the time or is it intermittent? Sometimes an engine with a misfiring problem will trigger a code 48.

Make sure you don't throw away a perfectly good LAF sensor when it may be something else is really at fault.

gork57 - you can get original L1H1 sensor from quality_auto_parts on ebay for $180 shipped:
https://myworld.ebay.com/ebaymotors/quality_auto_parts

See my post in this thread for details
https://www.gassavers.org/showthread.php?t=2121

Ross

Here's the procedure to reset the ECU.

Engine off. Under the hood is a fuse/relay box, on the passenger side near the firewall. Inside is a fuse marked "BACK UP."

Remove that fuse. Wait 10 seconds. Put it back. You're done.

CEL stays on all the time. The shop I took the car to is honest, and specializes in Hondas, so I do trust their evaluation. The price they quoted is simply outrageous-especially for something I can DIY.

When you put the new one in, the service manual indicates it should be torqued to 33 lb-ft.

Also, it's a good idea to cover the threads with anti-seize lubricant. You can get a little tube of Permatex Anti-Seize Lubricant 133A. That product is designed to work right with O2 sensors. Don't use a product that isn't known to be sensor-safe.

You can use that same stuff on spark plugs.

A nice selection of O2-sensor tools is here: https://www.sjdiscounttools.com/vehic...sor-tools.html

I got the socket-style, but I wish I had gotten the crows-foot style. I think it would work a little better on my car (VX).

We just took a deep well socket and cut a rectangular hole in it for the wires and plug. not sure if it would work on a 5 wire and my senso should be good for another 100K. I guess I will see if it works then.

regards
gary

Thanks all for your assistance. I should be able to take it from here. Great to find a place with views on fuel consumption similar to my own. GasSavers.org is a godsend!

As for O2 sensor sockets, I found this nifty 22mm set on Amazon:

https://www.amazon.com/OEM-27110-Oxyg.../dp/B00062ZK5M

This set comes with both "deep well with slot" and "crow's foot" style sockets. I'm an Amazon Prime member, so it will only cost me about $20 to have it shipped to me tomorrow.

Postscript: I replaced the LAF sensor last week. I followed all my fellow posters recommendations. The old VX now runs much better than before-no Check Engine light, much smoother idle, and I'm able to get the rpm's up when slipping the clutch to get going from a standing start up hills again! There's no substitute for having the correct tools to do a job; it only took about 20 minutes to take care of this one.

Considering how much it cost for the OEM LAF sensor (even the item mentioned by djenyc, which is less than what I paid), this is not something a DIY mechanic should try to take shortcuts on. The LAF sensor on the VX is a major part of the technology that enables this model to get such outstanding gas mileage. Make sure to use proper tools and installation protocols, and the job will go smoothly.

If your sensor is the same size as mine you can take a boxed end wrench run plug and the wires through the opening right down onto the sensor. No special tool needed.

On some cars that would probably work. But the VX 5-wire sensor has a bulky connector at the end, too big to fit through the wrench.

Also, it's a good idea to torque the new one to spec, and that's basically impossible without the right tool.

The right tool (either a socket with a slot, or a crow's-foot socket) will also help deal with clearance issues. On a VX with A/C, space in this area is a little tight.

I've heard Autozone will loan you the tool for free.