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Pre Cat 02 Sensor problems, (Need Input)

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  #21  
Old 01-14-2013 | 08:29 AM
tofast2belast's Avatar
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did you try clear the code, and when your having the car jumped, leave the 2 cars connected with the jumper cables and see if the code comes back? or remove the negative terminal wire from your battery and hook it to the jumper cables and see if code comes back.

- just trying to rule out possible battery cause.

also a side note, the car will fail if you say the battery is shot. each time you jump it, the readiness state is being reset also. and the battery being shot puts quite a bit of strain on the alternator.

heres a pdf for wiring diagram

http://www.dj-sures.com/GraphicFiles...tics/Horns.pdf

its on page 78/8.
 

Last edited by tofast2belast; 01-14-2013 at 08:53 AM.
  #22  
Old 02-16-2013 | 04:22 PM
HulkB5's Avatar
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I'm back home for the weekend and had to figure out my car situation.
I took apart the connections up at the ecu and traced back the wiring from the pre cat 02 sensor which is the blue wire in the picture here.
It had been tapped into and run into the dash somewhere.
Why anyone would do this is beyond me. The grey one next to it is still connected.

"Locate pins 1 and 2 on the sensor side of the connector (these pins are wired to the sensor's heating element, pins 3 and 4 are used for the sensor's oxygen level signal)"

So 1 and 2 are connected, as shown below and so is 3. But 4 is the one that is clipped.
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  #23  
Old 02-16-2013 | 05:03 PM
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Probably ran it into the dash to use one of those shitty A/F meters.
 
  #24  
Old 02-16-2013 | 05:06 PM
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i traced it runs to my Lc-1 which i have my wideband hooked up too. So maybe it send a signal from the wideband.
And i have my wideband currently unhooked. which is maybe why i am having this issue?
 

Last edited by HulkB5; 02-16-2013 at 05:50 PM.
  #25  
Old 02-16-2013 | 06:11 PM
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This is what is definitely going on, and most likely the reason why i have no signal.


Connecting the LC-1 to simulate a narrow band oxygen sensor. - 18 -
It is possible to install the wide-band sensor in place of the OEM oxygen sensor. In this case the
meter's analog output signal will replace the OEM oxygen sensor's signal to the fuel injection
computer. EFI equipped cars typically incorporate a narrow band oxygen sensor. These sensors
are typically 1, 2, 3 or 4 wire sensors.
The analog output connector of the LC-1 can simulate the operation of a narrow band sensor
while the wide-band oxygen sensor is installed in place of the OEM narrow-band sensor. Factory
equipped Analog output 1 of the LC-1 is programmed to simulate a narrow band sensor. Some
vehicles are equipped with oxygen sensors that do not produce an output voltage but change
their resistance depending on exhaust gas content. These sensors cannot be simulated. They
are used in less than 1% of all vehicles. Refer to your vehicles specifications if you think that
your vehicle may be in this category. The same is true for vehicles already factory equipped with
a wide-band oxygen sensor. These cannot be simulated either.
Some EFI-computers will create a fault when the heater power wires of the oxygen sensor are
disconnected. In this case mount the old oxygen sensor in a safe place (but not necessarily in the
exhaust) and connect the heater wires to it to keep the EFI-computer happy.
Be careful where you mount the stock sensor, as heated sensors will get
hot.
To connect the LC-1 to the EFI-computer, first determine what kind of narrow band sensor is
used, then follow the instructions below (you will need a digital multimeter to determine correct
OEM sensor wires):



c. Vehicle has a 3-wire sensor:
Typically the 3 wires are: heater power, Ground, and sensor element connection.
Generally they have 1 black wire and 2 white wires. Connect the black wire from the EFI
computer to analog output 1 of the meter. Leave the other wires unconnected but make sure they
cannot contact any metal parts or see above. If the wiring colors are different, then heater power
can simply be determined by measuring the voltage on the wires when the engine is running. The
wire showing 12V or more is the heater power. The sensor element connection voltage fluctuates
around 0.45V when the car is warmed up. Wire analog output 1 directly to this wire. The Ground
connection has low resistance to chassis ground (less than 1 Ohm). Measure while the engine is
off.

d. Vehicle has a 4-wire sensor
Typically the 4 wires are: heater power, heater ground, sensor ground, and sensor element
connection. Proceed as for the 3-wire sensor.
 
  #26  
Old 02-16-2013 | 07:32 PM
Mad Cow's Avatar
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That would be it, but why didn't you just get a new wideband sensor if you have an LC-1? They can be had for around $60 on ebay, cheaper than the majority of narrowband sensors.
 
  #27  
Old 02-17-2013 | 02:31 AM
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Ok, so i tried just running the wide-band hooked up and it still ran like crap.
so i hooked both of them up and it runs so great and idles better than it ever has.
But now whenever i shut the hood hard while its running or the door enough to jolt the car the car dies or something weird happens like open circuit on one of my fuel injectors.
or not enough fuel.

And i'm wondering if there's moisture in the ecu causing these problems. Because there was definitely and abundance of it when i took the box apart.
Is there any better way to seal these?
Ill take it apart tomorrow to see if there's actually water on the board.
 
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