Wow that is insane. 5mpg = ~75 miles per tank. I would just unplug the o2 sensors altogether and see if it made any difference. I ran my car for a couple of months with no o2's and got about 12mpg city, always in open loop.

Something i just noticed

Since when can you use wideband o2 sensors with the stock pcm ?

 

You ran for a couple months in open loop and you saw 12 mpg city. When you were in closed loop, what was your mpg?

sorry?

 

When I was letting it use the busted o2 sensors, the right one would randomly die out, and the ecm would throw in a ton of fuel and almost stall the car. It would only happen once in awhile, but it's pretty scary to be pressing the gas pedal and getting nothing. The mileage would vary wildly from tank to tank while they were plugged in, due to them cutting in and out.

And in your first post you mentioned wideband o2 sensors...

You didn't just plug wideband o2's into the stock computer did you? Because I do believe that would cause some problems. I'm assuming you just mean an wideband o2 sensor kit added in for tuning purposes, but I wanted to ask ya anyways.

 

I ordered Innovate LM1

Here is the link: http://www.innovatemotorsports.com/products/lm1.php

Is that okay?

BTW my O2 sensors are brandnew, but I should try unplug them and going with open loop. Today I drove 20 miles in the city (in traffic) then calculated it was 2 MPG in city!
US Gallons = 3.785litres right? not 4.546?

 

1 US gallon = 3.8 liters rounded up.

your telling me you used over 7.5 liters on a 32 kilometer trip?

 

Nope, 24 liters on a 32 km trip in city! (is equal to 2-3 mpg)

 

something isn't right... my buddy's dad's 502 bowtie chevelle with a huffer and double holleys stickin out of the hood gets better gas milage then that!

 

The wideband won't work with the stock PCM. This is a handheld unit that works completely on its own. I actually have the exact same wideband setup. I figured you'd get the gauge (LC-1), but this will work fine. I got the handheld so that I could tune other people's cars eventually.

 

Sorry I couldn't get it. So the LM1 will not work on my car?

 

The LM1 will work the same as the LC1, but it is a hand held unit versus having a gauge that you could mount in the car somewhere. It's easier to tote around and use on other people's cars.

 

Oh thats right. Once I see my AF ratio, then I will not need anymore, so I don't need gauge style wideband I guess.