Since my VX 02 sensor always throws a CEL...

[add|ct]

Aside from the obvious of replacing it, I was wondering until I do replace it, what would happen if I just unplugged it? Wouldn't this just allow the car to run in open loop instead of it always throwing the CEL after the car has warmed up and creating an open loop anyway???

[Project84]

What's the difference? Seems like if you're expecting the same results, why bother?

[add|ct]

One reason is to avoid worrying about killing the CEL every time it happens, but I suppose that's not all that important since you'd want to know if/when a new code is thrown. Okay, so the sensor is faulty, why let the ECU continue to try to make use of its 'readings'?

Part of the problem is I need a valve adjustment, but aside from that, it still does not feel like a smooth ride while from a stop and/or it seems to fall out of lean burn more easily than it perhaps should. I know the VX is a picky car to begin with, here. My guess is that the ECU is constantly trying to implement lean burn and isn't able to do what it wants to because of the sensor, thus creating an 'in between' sensation other than a VX with a functioning sensor.

This is all from the question I asked myself: Does the VX implement lean burn at all if the sensor is faulty or just to a less efficient degree?

[GasSavers_BEEF]

my understanding (not honda based and all OBDII) is that if the ECU is throwing a code, it is ignoring the sensor readings all together and using a pre programmed fuel map that usually runs a little on the rich side as to not cause detonation.

without a sensor, you have no feedback
with a faulty sensor, you have no feedback

either way, it is ignoring the readings and doing it's own thing. I would assume that your car hasn't gone into lean burn since you have had the bad sensor.

I know on my car, if I unplug the o2 sensor, I will throw a code almost immediately. not sure about OBDI cars but I would assume so. I agree that you want to keep the CEL off but I don't think you can do that until you replace the faulty sensor.

[add|ct]

That's what I needed spelled out for me. I didn't know for sure, but suspected as much. Well, I guess it says a lot about these cars to be getting over 40 MPG consistently without having a good sensor since we bought the car.

I'll eventually break down and buy the NTK/NGK one, but won't spend more than $200.

I wonder what the life expectancy is on those compared to the cheaper 5-wire wide band sensors for the VX?

[GasSavers_BEEF]

theholycow (the member) used to have a link in his signature for a $100 one that several people said worked well. even the california VX models got really good mileage. the california version couldn't use lean burn due to california emissions.

form a cost prospective, I would go with the $100 one because if it does last just 2 or 3 years, it would be worth it and then spend another $100 to get another one. they may last just as long too. I would just bite the bullet and get the sensor replaced so you can start seeing better mileage and you get your CEL back for actual problems that could cause serious issues.

I have seen several VX guys in the 60s and 70s for MPG.

[add|ct]

Yeah, that and a valve adjustment(eventually learning to do it myself) and I'm hoping to get 50+ consistently as a minimum goal.

I'm also running on older front tires with relatively low PSI(40), so that hurts potential FE gains where more PSI would be advantageous. Currently, I'm only at 40 on the front because the rear can only hold 36 max and I want the ratio to be close to the factory specs for ride comfort/suspension considerations.

The rear tires that were on the car I had moved up front to replace 2 worn tires, and for the rear replacements I purhcased 2 of those typically lame; for all intents and purposes, Primewell tires, because I needed 2 right away when I first got the car and had other mechanical problems I had to invest in before my choice of tire was possible. So, the el cheaps went to the back and the surprisingly good tread that was left on the Via2 Goodyear tires went up front. The previous owner(s) probably didn't rotate them, not even once. Those tires are really old models.

I'm also due to replace the outer tie rods & boots, ironically, so will need an alignment after those are replaced(as I'm sure its due for one as well, looking at $300 for those things), so instead of wasting the alignment on the current tires I'm holding off for all of that work until I can get a set of 4 tires that I want. So, if I invest $200 in a good set of 4, I've got an estimated $500 in parts/service for all of those things related to each other to budget in.

So, it may behoove me to save on the sensor like HC recommends that others have gotten with decent results. Still, compared to the $350 price the NGK site asks for the same sensor/part number; and we all know the $500+ the Honda dealer 'requests', to me $200 is on the lower end already for the NTK model. If I can squeeze the extra $100 I may buy that instead, but won't go over that.

Aside from those things, I want to patch up any body work issues/fix my hood 'problem'(its off for some reason on the driver side and I get some wind drag at highway speeds), and get 'er repainted like the Thrifty McGassaver someone else has on the site well, it'll all be caught up finally.

[cems70]

Originally Posted by BEEF

theholycow (the member) used to have a link in his signature for a $100 one that several people said worked well.

I recall reading a post in the last 2 or 3 months about that $100 O2 sensor's price having increased to $199. I purchased two for my '98 HX a couple of years ago when they were $99. One is a spare for when that other one dies.

[theholycow]

There are now two links for cheap O2 sensors in my sig. I have not purchased from either company or used either sensor, so I cannot vouch for them, but they have success stories from users on this forum. I think one may be $79, even...I don't remember.

As for unplugging, that would absolutely continue throwing a CEL on an OBDII vehicle, but I don't know the VX. As BEEF said, on OBDII it would also result in open loop operation.

[add|ct]

I'd imagine the same thing would happen with the VX. Even plugged, its not functioning right, so long-term its best to replace that and get my valves adjusted after the fact, especially seeing as how often maintenance checks are required on the valves.

My mechanic even said himself that they don't recommend coming in every 15k for the VX, just because its overkill and a waste of my money.