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O2 Sensor Problems

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Old 07-30-2004, 01:29 PM
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Default O2 Sensor Problems

Ok I think this is where I should post this...

I have the Dynatech Headers on my AV and keep blowing me rear O2's... I have gone through 6 in 2 months now. I put a new one in.. reset the PCM with the Superchips and within a week or 2 I get the SES light again and pull up code P0157- low voltage sensor 2 bank 2. What gives?? I have replaced them even tried the O2 sims and the sims cause 3 diffrent codes.. P0153,P0155,P0159

Can anyone steer me in the right direction?? I am sick of that SES light and now my A/F guage bounces wildly from rich to lean and I am almost ready to take it out because of how anoying it is. Please help me...

Bonedog
Old 07-30-2004, 02:36 PM
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Hmmm, at first I was going to say the LT's may be the problem. Are the Dynatechs coated? I know some people have had problems with their uncoated TOG's, but you're rear O2 sensors (past the cats) are buggered up? Some folks have had less than desirable results with teh O2 sims, maybe they can help out.
Old 07-30-2004, 02:40 PM
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Ah, I see you're also running the high flow cats! Maybe they're attributing to the problem? I don't think too many of the truck guys have the high flow cats. Maybe the external engine forum can help?

Good luck! Every once in a while I'll throw an O2 sensor code (No SES light)and I'm supposed to have them deleted.
Old 07-30-2004, 02:42 PM
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The cats are the highflows that come with the Supermaxx system. And no my headers are the stainless that the Dynatechs are made out of.
Old 07-30-2004, 02:48 PM
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Originally Posted by Bonedog
The cats are the highflows that come with the Supermaxx system. And no my headers are the stainless that the Dynatechs are made out of.
I should've know that!

Maybe the exhaust is cooling down (like the uncoated TOG's) and causing the O2's to read wrong? I haven't heard of this problem with the Supermaxx system.
Old 07-30-2004, 02:51 PM
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My passenger side rear O2 just threw the same code a few weeks ago and I also have the FLP/Dynatechs. I just deleted all the associated codes with LS1Edit so the light would go away. I don't know what could be causing the problem though.
Old 07-30-2004, 02:55 PM
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Originally Posted by XLR8NSS
My passenger side rear O2 just threw the same code a few weeks ago and I also have the FLP/Dynatechs. I just deleted all the associated codes with LS1Edit so the light would go away. I don't know what could be causing the problem though.
Wish i had someone to do edit for me... I would love to lose this stupid SES light and get my damn A/F ratio back to normal. i am afraid if it keeps running this way I am going to blow or burn something out.
Old 07-30-2004, 02:59 PM
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The O2 sensors jump back and forth under part throttle operation from rich to lean so that is normal. I've never had one of those AFR guages but, it should jump around alot at part throttle. Under WOT they should be steady though.

The rear O2 sensors have nothing to do with fueling though, they are there as a diagnostic aid to make sure the cats are working right.
Old 07-30-2004, 03:02 PM
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so with the sensors being F-d I shouldn't have a problem with the truck?? Does it stay in closed loop or open loop with the SES on? If its open loop all the time won't that dump fuel and burnup the cats??
Old 07-30-2004, 03:05 PM
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If the codes are for the REAR 02(sensor 2) sensor you will have no problems.

The truck will still run in closed loop once it's warmed up.

As long as you don't have any front 02 problems you will be fine.


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