O2 sensor

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Dec 4, 2003 | 09:03 PM

CrazyFordMan

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From: prince george canada

O2 sensor

i checked my codes the other day and it said that my o2 sensor was reading rich and lean (2 codes) so i looked at the sensor and notices a wire had pulled out of the sensor so off to the auto parts store i go to get a new o2 sensor. so i pick one up for $85

install it and then go to bed. i get in my truck to go to work the next day and that damn check engine light is on again so i pull out my trusty code reader and check my codes. ans waht do you klnow same code as befor " HEGO shows system always lean" does that mean that the o2 sensor is bad or is there somthing else wrong?? would that also hurt my milage???

Dec 4, 2003 | 10:42 PM

CrazyFordMan

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From: prince george canada

anyone??

Dec 4, 2003 | 11:07 PM

lexluthr69

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From: Newport News USA

Did you clear the codes after installing the new O2 sensor? Just remove the neg. battery cable for 5-10 mins. What code are you getting? If it's a code 41, then that can often be misleading. It means that it's sees a lean condition while Running, and/or that it's a continuous memory code for no switching detected. Check the ground that runs to the back of the driver side head. That is the ground for the O2 sensor signal return. The ground should run from the back of the head, to the wiring harness at the PCM. Then check all wiring that runs from the PCM, across the top of the radiator, and over to the passenger side wheel well, where it then runs down to the O2 sensor. An easy way to check to ensure your O2 sensor is working is to hook a multimeter to the signal return line on the sensor itself, and then apply heat to the sensor with a propane torch. If you see a change in voltage, the sensor should be good to go.
Make sure the codes are cleared, and if it's still present, then start checking the wiring for it.

Good luck,

Luke

Dec 4, 2003 | 11:30 PM

CrazyFordMan

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From: prince george canada

i got code 172 and yes i cleared the codes

Dec 5, 2003 | 08:00 AM

lexluthr69

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From: Newport News USA

Then I'd check the wiring. If you find that to be satisfactory, then we get to move on to more challenging stuff. Have you actually tested the sensor on the truck, to see what it's doing? Along with testing many other parts in that realm of the problem...