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Discussion Starter · #1 ·
Anybody know what the resistance of the o2 sensor should be?
 

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the heater circuit? Or the other side? ANd if you are inspecting it, you should check the voltage flucuations when the car is at idle.
 

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Discussion Starter · #3 · (Edited)
BoostedBoxer said:
the heater circuit? Or the other side? ANd if you are inspecting it, you should check the voltage flucuations when the car is at idle.
I am not sure which side I am afraid I could have bumped the wiring or something, when looking for a part. Of course the CEL says fuel pump electrical malfunction, but that could be cause by something else like the wiring for the o2 sensor, who knows heh. The only reason I suspect it is because my car started acting funny after I was messing around that area, looking for a part I dropped. All I know is I had my hand down there and I bumped it a few times, looking for a round metal piece for the air box and now my car says the fuel pump is malfunctioning due to an electrical problem, so I just need to find out wtf I did heh.
 

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Discussion Starter · #4 · (Edited)
BoostedBoxer said:
the heater circuit? Or the other side? ANd if you are inspecting it, you should check the voltage flucuations when the car is at idle.
Also what should it do as far as voltage goes when the car is at idle if it is functioning properly and also what is the best way to test your MAF sensor as well? I have a multimeter and I know how to read voltage and resistance and current, so if you could just lead me to the right leads to check.
Thx
 

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lets see here- WIth out looking at the manual, the 2 black wires (on the o2) are the heater circuit so check if those have any resistance at all. If its open, then its bad. As far as checking the voltage on the other side (should be white and black) You need to back probe it with some pins (both wires) and set our DVOM to dc volts. After the car is well warmed up and has been runnning for a while, check that the voltage cycles from low voltage to high voltage constantly. It should be always cycling. Have some one rev it up and make sure that it responds be the voltage going high and staying high (rich condition).


Edit- this only works with the 02 on the manifold- the rear one is a different story depending on your mods.
 

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Discussion Starter · #7 ·
BoostedBoxer said:
lets see here- WIth out looking at the manual, the 2 black wires (on the o2) are the heater circuit so check if those have any resistance at all. If its open, then its bad. As far as checking the voltage on the other side (should be white and black) You need to back probe it with some pins (both wires) and set our DVOM to dc volts. After the car is well warmed up and has been runnning for a while, check that the voltage cycles from low voltage to high voltage constantly. It should be always cycling. Have some one rev it up and make sure that it responds be the voltage going high and staying high (rich condition).


Edit- this only works with the 02 on the manifold- the rear one is a different story depending on your mods.
Very informative and I know the rear o2 sensor is fine. Now when you say make sure the circuit isn't open you are saying the circuit fails in an open state (really high resistance). If it is just a resistor like the ones at radio shack they usually fail closed (short) or lessened resistance. At least this is what I have experienced. DVOM I am assuming is same as DMM digital multimeter or Digital voltage ohm meter. Thank you for the tip on the wire terminals too. Now I have to find somebody that can hopefully weld a stud back onto my gas tank :)
 

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Yes DVOM= Digital Volt-O-Meter

And if something is "OPEN" its got infinity resitance because there is no path. So yes it fails in an "OPEN" state. What brand DVOM do you have? It should say open or error or something. Make sure when checking for resistance, its on ohms.
 

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Discussion Starter · #9 ·
BoostedBoxer said:
Yes DVOM= Digital Volt-O-Meter

And if something is "OPEN" its got infinity resitance because there is no path. So yes it fails in an "OPEN" state. What brand DVOM do you have? It should say open or error or something. Make sure when checking for resistance, its on ohms.
Well as far as I can tell the o2 sensor is fine, and I tried another wrx's MAF sensor and it did the same thing. I also noticed a breather or vacuum line that sits on top of the fuel railthat was disconnected. I pluged it back in with no positive results. I guess my next step is to send the fuel injectors to company that makes them to have them checked. I checked one of my spark plugs and they were .028 so they were pretty much perfect. I did notice it was white on the end of the spark plug = not getting enough fuel, which I already knew, but still don't know the cause. And I noticed it happens at WOT AND partial throttle now. Partial takes higher rpm to misfire about 5500, where WOT is more like 4500.
 
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