First Tank MGP results!

[coletrain777]

So, I finally got my o2 sensor for the vx, and decided to take a trip to pick up a few parts so I could see what type of mileage it would get. The trip was 90% hwy at 65-70 mph most of the time. I hooked up my voltmeter so that I could monitor lean burn and took off. I didn't use any special driving habits except for keeping it in lean burn for almost the entire trip (probably only kicked out for 3 total miles).

I figured with us still having winter gas, and me not employing and driving changes other than slowing down a tiny bit I would probably end up at around 45mpg, boy was I wrong. I just filled up and the end result is... 53.44 mpg. I drove 398 miles and it took 7.447 gallons to fill up. I filled up before I took off and filled the tank to where I could see the fuel in the neck (to the top), and filled it to the same spot when I re-fueled.

I know I have to take an average to see where I really am mpg wise, but I am pretty impressed at this mpg.

Just thought I would let you know

[LarryJ]

Thats awesome Coletrain! I've never seen better than 45mpg in my one year of driving a VX and I don't typically drive over 60-65 mph.
I'm curious, what action do you take to put the car back in lean burn if the meter indicates that you're not in LB. Do you just slow down?

Note to self, figure out if my VX is running in LB.

[coletrain777]

LarryJ,
I was really impressed with the mileage the little car got. I just bought it a couple of weeks ago, and it had a bad o2 sensor. My first tank with the o2 sensor unplugged was about 38mpg (mostly highway at 70mph). I then installed my replacement o2 sensor and went on this road trip and it netted me 53.44 mpg!!! As far as staying in lean burn, I have my voltmeter hooked up to the D14 and D1 pins of the ecu and it tells me when I am in lean burn. As soon as I gave the car too much throttle and it kicked into VTech mode I would immediately take my foot off of the gas and let it re-enter lean burn. Depending on the incline I could stay in lean burn most of the time between 65-75 mph.

One thing to remember is that I live in a very flat area for the most part. A small incline in your area would seem like a mountain to me. It's for that reason that I don't do any EOC, there is no hill within 150 miles of me that would allow me to coast for longer than 20 seconds.

[LarryJ]

ColeTrain,

have you noticed if the car is in lean burn during acceleration; 1st through 5th?

Also, do you know of a way to test O2 sensor while it's in the vehicle. Do they gradually decline in performance, or when it dies, does it die completely?

[i-DSi]

Originally Posted by LarryJ

Also, do you know of a way to test O2 sensor while it's in the vehicle. Do they gradually decline in performance, or when it dies, does it die completely?

Hi Larry, normally these sensors die gradually because carbon builds up on it.
I read on a forum you can try cleaning them with vinaigre (tip of sensor in the vinaigre). Also read you need to rev the engine a couple of minutes after cleaning to allow all carbon to be blown away.
If they die they sometimes react very slow to changes in the mixture or consitently give a too high or to low voltage. In the end an error code comes up.
Don't know how to test them.
I believe some manufacturers include new sensors in the maintenance schedule (BMW I think) in the 90's (after 100k km). Honda doesn't as far as I know.

[benfrogg]

I have a question-
Which 02 sensor did you put in? How much did it cost and where did you get it? I've got the $80 jobby from Holycow's profile link in mine. Wondering if I need to pony up for the $250 one.
Thanks

[theholycow]

I'd be very interested to find out if something's wrong with the one they're selling at that discount price...I wouldn't want it in my sig if it doesn't work right.

[shatto]

This whole thread is Greek to me..........except the MPG.

What are you doing that I can do on the Tundra's 4.7 engine?