VX O2 sensor reading to wide?
 

Hello, I am new here but have been getting lost of ideas and answer from here so I thought that it would be more helpful to join. I get right to the point...I bought a 92 VX about 3 months ago, when I bought it it had set for 2 years and need the trans rebuilt. So I rebuilt the trans, put on a timing belt water pump, and plugs, wires, cap and rotor. All of course made in Japan or Germany. I also installed a multimeter for the O2 sensor voltage to tell when I was in lean and also to be sure the O2 was working right.

Now here is my problem....after the car is warmed up, when I am driving in lean it reads any where from +.8 to +1.2 but when it senses load, like a small hill or something it will go straight to -1.0 to -1.2. now that is with not even pushing any more on the gas. Now this is how it runs all the time it is ether at -1.2 or at +1.2 there is no in-between, its very rich or very lean. I also have no check engine light on.

Now from reading a few other posts on their readings, it seems to me that my O2 is bad. But I wanted to get your option on this to be sure before I go out and but a $200 sensor. Could it be something else or....? thank you

Re: VX O2 sensor reading to wide?
 

Does the upshift light work? Does it work all the time?
The ECU does change fuel maps even without extra throttle if it senses a load event.
Lean burn is kind of funny. It is far leaner than most cars will ever get to in lean burn. However, in it's "power" mode that isn't lean burn, it burns more fuel than the other typical hondas of this era.
I can't speak to the voltmeter specific readings, but it's possible the 02 is tired but working.
Either way, don't buy the $200 sensor. I bought it to replace a >$80 sensor. They functioned exactly the same way. The cheaper sensor is made by Standard and is model SG335 if I remember right. I bought it at the local new england store, Motor Supply of Augusta, ME. I've still got it if you want to try it on the cheap.

B

Re: VX O2 sensor reading to wide?
 

^Yes, it's hard to find that sensor for sure. I bought one on RockAuto for about $55 last year and since then it has disappeared.

Re: VX O2 sensor reading to wide?
 

Did more research, it appears SG2165 is a 'more expensive' superseding part than the SG335(which is hard to find), though I did see a stash on Amazon.com right now for dirt cheap compared(the SG335 that is). Makes you wonder if they feel the SG2165 is superior/more compatible(???) or just a means to make more money and a more 'exact' to OE sensor replacement(the prev. not/though now Bosch made 5-wire that is minimally $300+...$500+++ at dealer etc)....

If I had to pay more than $100...I'd buy a Denso or NTK/NGK replacement($150-$200) than the Bosch or dealer offering; sorry it makes me go from feeling robbed to murdered.

PS: The SG2165 is over $300 and the SG335 is less than $100 on Amazon, other sites say they don't have the SG335 in stock and get you buy the 'alternative' SG2165...ugh no thanks.

EDIT: Oh well, the Amazon offering disappeared after my post...figures!

Re: VX O2 sensor reading to wide?
 

Good job on the research! Yes, the SG335 seems tough to find. They may have discontinued it. I can ask the local place I got it next time I'm in the shop.

I'd sell mine with about 5k on it for $30+shipping if you just want to try one that is known working. It's in good shape.

Seems the sg 335 was discontinued and replaced by the newer number, 2165. Someone probably figured out they could make a lot more money than they were on the SG 335 since it was way cheaper than every other model available. So, make a new part number and voilla, new, 5x more expensive part that is likely identical. That sucks.
I did testing with both sensors (a/b/a) and there was no appreciable difference on the 'guino in terms of mpg's. Lean burn still worked, etc.

B

Re: VX O2 sensor reading to wide?
 

^My wife told me we should have stocked up on the RA site offering and held off until it was too late. Well, I hope someone else enjoyed the break in price too. Nice of you to share the love ben. :D

I have heard that the NTK/NGK flavor is more 'responsive' or sensitive to more minute changes in voltage inputs etc...but that may be just marketing re-stated through folks like myself that haven't done the testing.

Re: VX O2 sensor reading to wide?
 

I used a cheap ebay sensor for a long time with excellent results in my 91 d15z1. I had a similar problem.

Re: VX O2 sensor reading to wide?
 

Thankz for all the info and the offer on the O2 sensor. I went ahead and bought a Denso from RockAuto for $170. Am still waiting to receive it, they sent me the wrong part so looks like it will be another week till I receive it. :( After it is installed and I get the new reads I will post the info.

Also, I like the mods you did to your VX benfrogg. How much did it improve your mpg? I was thinking of doing somethings like that to my VX later down the line.