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1994 GMC Jimmy

Question: Oxy sensor/s

Question

papa63, Colonia, NJ, April 19, 2009, 10:33
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 Rookie

Hi, i have an 1994 4wd Jimmy slt 4.3 liter. Is there two oxy sensors or just one. It all of the sudden runs poorly and seems to miss and gas mileage is down as well. Any help with this would be thankful. I tried to get any stored codes but there are not any stored.

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  • Answer #1

    dandd April 19, 2009, 13:47
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    I would have the vehicle properly scanned. What criteria are you using to determine if it is an Oxygen Sensor problem. These vehicles have several things that can cause them to run poorly and get bad mileage.

    If you have a bad Oxygen sensor, it would set a code, usually a code 13. A code 12 means all clear and no tach signal until engine is started. ( again normal )

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    papa63, April 19, 2009, 17:50
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    I used a jumper wire from terminal a to b on the obd-I connector and had no codes stored. Kept flashing code 12.

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    Visitor, October 28, 2010, 15:40

    Jumping the and b connector is not a scan, I mean use a scanner to see live oxygen sensor operation, to see if it's quickly 'cross counting' above and below .450 volts. If it hovers below .450 volts, then there is a problem. This vehicle is an OBD-I system so the codes are not in the P0131, P0141 format., as suggested below. An oxygen sensor code for a 1994 4.3 liter Jimmy is a code 13. Also, according to the GM Service manual this is a 1Oxygen Sensor System, so the bank 1, bank 2 info below is misleading. Again, have a real scan of your engine, that will give you a WORLD of information.

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  • Medium-star Best Answer
    jose jr June 25, 2010, 18:24
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     Enthusiast

    gengeral o2 sensor malf:13,44,45.left bank sensormalf:po131,po132,po133,po134.rigth bank sensor malf:po137,po138,po140,or po141.catalyst o2 malf:po143,po144,po146 or po147.For proper operation of o2 sensor depends on four conditions:Clean eletrical connections with sensors,2.outsde air supply ie:make sure air passages are not retricted to sensors(to the internal part of the sensor)3.proper operating temperature(the PCM will not react until temp reaches appro.600degrees-f 4.unleated fuel must be used for proper operation of sensors.

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  • Answer #3

    Visitor, September 20, 2010, 11:57

    there is two o2 sensors just took mine off seems to run rich if anyone knows a fix please help

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  • Answer #4

    Visitor, October 28, 2010, 11:29

    I have a 94,4.3cfi 4wd,mine has one sensor onthe rigth bank.It is hard to see because its on top of the cat.theres a shield that covers the cat which makes it hard to get to,it has four wires coming from it.My engine was doing the same thing so i check the egr valve,because the gase from the engine sometimes producelittle metal pices that can make the pintle in the valve stisk open and allow to much air into the intake,theres a gasket you can buy that has a screen to cover the opening of the air flow that would stop this from happening.I also had no stored codes ,the check engine ligth wasn't communicating with the pcm,so i replaced the pcm myselp cost around $90.00,its not that hard to change.the service engine ligth started working and gave me a code which told me the IAT sensor was bad.sensor cost about $10.00 located in the air tube leading to the plelum on the underside of the hose,i changed it and the car runs fine,hope this gives helps you! good luck

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