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Old 12-19-2016, 09:10 PM   #1
dec010974
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A bunch of hot air

Hello to all. I need help with my LSx o2 sensors. As I look at the scan gauge on my LSx swap, I noticed that my O2 sensors aren't responding to the PCM. My exhaust Is open due to the fact that I was rejected by the muffler shop due to leaking gas from the fuel sending unit. The loose AN fittings was tightened, fixed. Is there any reason why the 02 sensors are dead? I would hate to buy new sensors and not Resolve the issue. Thanks in advance, Clark. I did the harness myself.
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Old 12-19-2016, 11:16 PM   #2
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Re: A bunch of hot air

How close to the open end of the exhaust? I wouldn't worry much till the pipes are on.
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Old 12-20-2016, 02:00 AM   #3
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Re: A bunch of hot air

are you sure that you didnt program the o2 sensors out of the computer?

I ask because when i had my computer re-programmed i had the aft o2 sensors removed as emissions compliance is not necessary.

-Izzy
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Old 12-20-2016, 10:20 AM   #4
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Re: A bunch of hot air

Big port jimmy 6, the 02 sensors are very close to the end of the open exhaust. Also the tuner stated that the 02 sensors aren't responding. Izzy Briton, I'm referencing the front o2 sensors. The rear sensor will be removed from the tune.
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Old 12-20-2016, 11:02 AM   #5
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Re: A bunch of hot air

Why do you think they are dead?
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Old 12-20-2016, 06:30 PM   #6
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Re: A bunch of hot air

Hart_rod, the scan tool has a listing/display that shows the activity of the o2 sensors of live data. While the engine is running, The data or activity of the o2 sensors Will be bouncing around, calibrating itself as the engine runs. I was told that the o2 sensors activity, ranges from 5 thru 450, which means rich or lean as the pcm interpret this info. I may have left out a thing or two but the geeks will know what I'm talking about. You gotta love the smart guys. They built this country. In my case, the o2 sensors show this symbol (-). This symbol - is not a number from 5 thru 450. That's why I say the o2 sensors aren't responding. I'll check in the morning. The exhaust was installed today.
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Old 12-20-2016, 07:52 PM   #7
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Re: A bunch of hot air

Are they stock 02 sensors? The ( - ) means its not getting ANY signal from the 02. Any chance you've got em wired wrong?
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Old 12-20-2016, 08:40 PM   #8
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Re: A bunch of hot air

Brew city, I am offended. Me, wire the o2 sensor wrong? Brew, I never. Lol, I used GM schematics while fabbing up the wire harness. I did change from the square sensors to the flat o2 sensors. The wiring is as follows d-ignition, c-harness ground, b-#66 or#69 pcm, a-#26 or #29 pcm. What's next brew?

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Old 12-20-2016, 10:32 PM   #9
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Re: A bunch of hot air

Check the fuse panel. They can pop the Engine Sensor Fuse, 10a
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Old 12-20-2016, 11:53 PM   #10
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Re: A bunch of hot air

It should display a Voltage Value, Unplugging the O2's should yield close to 450 MV (Open Circuit).
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Old 12-21-2016, 08:42 AM   #11
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Re: A bunch of hot air

Brew, it can't be that easy as just exchanging a fuse. Hard is the story of my life. Cline I'll check the millivolts. I will also check the continuety of each wire and unplug/plug each 02 sensor. Thanks Fam. I'll post the results.
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Old 12-21-2016, 08:49 AM   #12
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Re: A bunch of hot air

Quote:
Originally Posted by dec010974 View Post
Brew, it can't be that easy as just exchanging a fuse. Hard is the story of my life. Cline I'll check the millivolts. I will also check the continuety of each wire and unplug/plug each 02 sensor. Thanks Fam. I'll post the results.
I'm assuming you are getting a check engine light or no?
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Old 12-21-2016, 02:06 PM   #13
dec010974
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Re: A bunch of hot air

Alright boys and girls. I unplugged the o2 sensors, then plugged them back up prior to start up. I cranked the Motor and plugged up scan gauge. I saw 3 codes that deal mass air flow. I'm running a speed density tune. The o2 sensors are responding. They read around around .445 as clone stated. Clinebarger wins the prize. Thanks my c10 family. Happy holidays. The tune will come and adjust my tune now that The exhaust is buttoned up.
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Old 12-21-2016, 02:24 PM   #14
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Re: A bunch of hot air

Quote:
Originally Posted by dec010974 View Post
Alright boys and girls. I unplugged the o2 sensors, then plugged them back up prior to start up. I cranked the Motor and plugged up scan gauge. I saw 3 codes that deal mass air flow. I'm running a speed density tune. The o2 sensors are responding. They read around around .445 as clone stated. Clinebarger wins the prize. Thanks my c10 family. Happy holidays. The tune will come and adjust my tune now that The exhaust is buttoned up.
So there was nothing wrong
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Old 12-21-2016, 02:58 PM   #15
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Re: A bunch of hot air

You might want to try in the LS section:

http://67-72chevytrucks.com/vboard/f...play.php?f=206
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Old 12-21-2016, 08:32 PM   #16
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Re: A bunch of hot air

This is the LSx section. @ hart Rod, I guess I'm lucky. There was nothing to fix. The sun does shine on a dogs azz, sometimes.
Thanks again Fam.
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