o2 sensor malfunction from air/fuel guage

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Jul 15, 2004
  #1  
i installed a stochometer (air/fuel) to reprogram my fuel computer, and i had a "stalling" problem on cold start-up. i learned how to trick the stall without setting off the engine light. i thought the stall was a fuel filter, or a ing. coil, or somthing else. just to narrow down my "possable problem" list, i unplugged the air/fuel guage from the o2 sensor, and the stall dissappeared!! also i noticed "more power!" the connection from the guage was causing too much resistance in the wire, causing a mis-inturperted signal to the ECU.

so.....is there somewhere else i can tap this wire for the guage where it will not cause problems????
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Jul 15, 2004
  #2  
Quote:
so.....is there somewhere else i can tap this wire for the guage where it will not cause problems????
Directly into the ECU and no, I don't know how it's done but that's the best location.

I had to replace my o2 sensor because they gauge wrecked it. Had the same problems you did.
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Jul 15, 2004
  #3  
what do you mean? the tap needs to be 3-5 inches from the sensor....if i go all the way to the ECU, i will not get an accurate reading.

i guess i should haved asked;
"does anyone know of a o2 sensor that puts out more AMPS so i could tap into it?"
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Jul 15, 2004
  #4  
Unless you have a fuel management system I don't think you're ever going to get an accurate reading. The system varies constantly and as a result you'll see it go back and forth and likely not stay in one place for very long.
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Jul 15, 2004
  #5  
for what its worth, i had an a/f gauge on my old car and i tapped where the o2 sensor wire going into the ecu, about 3" from it. o2 sensors run off sending voltage #'s back to the ecu, your gauge might be throwing that off somehow by stealing a small amount of the signal, or maybe you cut one of the copper strands and its sending incorrect voltages back to the ecu because of that. what kind of a/f gauge is it? the only kind you should tune with are wideband o2 sensors. regular .94v type gauges or blinky light gauges arent reliable and accurate enough
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Jul 20, 2004
  #6  
Quote: for what its worth, i had an a/f gauge on my old car and i tapped where the o2 sensor wire going into the ecu, about 3" from it. o2 sensors run off sending voltage #'s back to the ecu, your gauge might be throwing that off somehow by stealing a small amount of the signal, or maybe you cut one of the copper strands and its sending incorrect voltages back to the ecu because of that. what kind of a/f gauge is it? the only kind you should tune with are wideband o2 sensors. regular .94v type gauges or blinky light gauges arent reliable and accurate enough
no wires got cut, i used a T-tap. apperently the problem was the T-tap causing too much resestance...sending a wrong signal. (as both you and i stated prevously) here soon i will search out the 1st o2 sensor wire from the ecu.
i don't have any major engine stuff done yet. (my profile ) i just watch where the needle peeks, and troughts, and estimate where the "sweet spot" is depending on throttle %. when i set my fuel computer up, i made guesses on the fuel % increase. as a result, when i installed the A/F gauge, i found that anything above 2200 RPM would go instantly to full rich. so it served it's perpose in getting the fuel computer set to a much more practical level. (peak was set to 10%, now a mere 5% is peak at 4800 RPM)

by buying/installing/un-installing this guage, i was able to set up my fuel computer "more" correctly than just guessing. i've saved the money i spent on guage/guage pod in fuel, because i have more power, and my gas millage has averaged an astonishing 39-41 MPG. ....for better tunning, i plan to visit a dyno soon.....

it's a megan racing guage. i don't know what a " .94v guage" is....this one reads between 0v and 5v.
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