So I measured my o2 readouts on the new VX..
 

and I'm not sure what to make of it.

at cold, i e a -0.8v readout

at idle after warmup between +.25v and +.3v

whats strange, when just maintaining 60mph w/ hardly any throttle, i get between +.93v and +1.05v

when slightly accelerating while already at 60, the readout goes to -.25v to -.29v




am i missing something here? i measured the readout just as described with pins d14(+) and d16(-). the numbers are nowhere close to what is supposed to readout. does this mean the o2 sensor is indeed shot and would hopefully explain the 40mpg mileage ive gotten so far

Here's what Krousdb had posted about his experience:
From what is said, it seems to be working, but you're getting into a super lean condition though. I'd PM Krousdb to see what sort of readings he got as I haven't hooked mine up yet.

Cold and idle readings are good. When entering lean burn you will feel a sudden loss of power and the DVM will read 0.4-0.45. It sounds to me that the O2 sensor is bad, but I don't know for sure. My bad O2 sensor was just stuck at -0.8 and never moved.

Well just to add to this I just hooked up my dvm and I am getting similar readings except the lean burn readings for me are .79 to .85. I am assuming that we get different readings because of every o2 sensor is a little different, I say that because although its a 5-wire sensor there are 2 more wires that go to a calibration resistor that is special for each o2 sensor... Or i could be completely off base and it could be any one of a million different things wrong with our cars(different fuel pressure, clogged injectors, slightly different ignition settings, ect........) Hope this helps :)

There could be a contributing factor of elevation difference as well.

As a side note, how were you both hooking up your DVM/DMM? I was thinking of just getting a spare set of leads and soldering them into the respective wires near the ECU.

yep, I cut a spare set of leads off my meter and soldered them into d14 for the positive lead and d16 for the negitive lead... I also got backlight dvm and velcroed it to my dash, now all i have to do is to convert the cars battery voltage to 9v and wire it into my meter so I won't have to replace the battery in the meter.....;)

update... I put in a brand new o2 sensor and now my readings are +.6 to +.7 volts when in lean burn. the readings are lower than the old sensor(old sensor +.79 to +.85 volts) I haven't noticed any gas mileage increase with the new sensor...

what mpg were you getting before you replaced the o2?

NickF829: Since I'm not running a VX, currently, I cannot comment based on direct experience. In looking at your numbers and in consideration of how my standard O2 sensor behave, I think your looking at a circumstance where you have some other sensor which is either not working entirely correct, or something. In any case, your readings, relatively, make me belive your not actually getting into lean burn, which means the ecu is thinking something else isn't Ok, for lean burn.

fyi I was getting between 44 - 50 mpg and its the same with the new sensor....

I forgot to ask: Are you using a driving style that would net a higher than normal mpg? or are you just driving the car like a regular car and shifting when the light tells you?

Given the fact that the FE of the VX is greatly affected by temps could be a factor at this time of year. But if you are driving the car without much FE technique the car is actually getting the mileage it should be.

The other things to look at now:
De-carbonizing the motor/intake manifold and EGR system.
Checking for proper gap and spark plug type (all listed in the VX lean burn monitor post in General Tech) VX Lean Burn Monitor
check condition of brake components for dragging
check condition of CV joints
Check air pressure in tires

That's all I can think of at the moment.

ive been driving without flooring it anywhere, i shift around 15-1600rpm, usually well before the light tells me to shift, i use the highest gear possible when city driving to keep the rpms there lowest. i figured doing this should net higher MPG

one thing i was wondering, is a 2000-2200 rpm idle at 60mph in 5th gear normal? seems my 95 civic EX is about the same rpm at the same speed

today, i did the pulse and glide driving all day, i put 150 miles on it, and at the end of the day filled up to get 52.3 mpg. does everyone have to use pulse and glide to get what the EPA recomends with these cars? seems like alot of work to reach only what the EPA says the car should get

also, ive already "seafoamed" the motor and manifold, it was dirty but didnt make a difference

replaced and gapped all plugs (the proper VX plugs)

not sure how I check the CV joints? there is a slight pull at speed, i need to figure out what that is

i got excited when i saw 52mpg today with the pulse/glide technique, i think i aggrivated quite a few drivers on the road who were following me, they probably thought i was drunk haha

i need to check the timing as well, seems sometimes going uphill, it feels like there is no power, or at least even less power then there usually is