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Need help!!! Driver side O2 keep adding fuel for unknown reason....

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Old Aug 15, 2012 | 02:41 PM
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4U2NV-SS's Avatar
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Default Need help!!! Driver side O2 keep adding fuel for unknown reason....

Quick break down of my set up..
99 Camaro M6
LS3 418 TSP
TSP CNC LS3 heads large cam
ported 102mm FAST manifold and PTM 102mm TB
SD at this time no MAF (trying to fix this problem with O2's, then put 100mm MAF back on)
104mm Lid

This is my exhaust
TSP 1 7/8 LT headers bolted to 3" cut out y-pipes (cutouts are closed) welded to 18" dynomax bullet sthen 3" turn downs pointed to the side on each side.

My problem is then when we (tuner and I) turn the o2's on the driver side starts adding fuel and within a minute of idling the drive side shows that 25%+ more fuel in HPTuners. I have replaced both o2's on each side to densco's and even swapped o2's driver to pass, pass to driver. Replaced those o2's under warrenty. But still have the same problem. Currenlty we have it tuned off my wide band and running open loop I believe.Wideband is on driver side header at collector about 6" up before o2 sensor.


Any ideas????
No intake leaks, no exhaust leaks, checked all bolts and welds.

My tuner thinks I may need to change my exhaust to a H-pipe or X-pipe and dump it before the rearend. I have ran this exhaust set up for over 7 years with my old set of H/C stock 346.

Kinda stumpped right now....

Thanks
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Old Aug 15, 2012 | 02:47 PM
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Have you tested all wiring related to the driver side o2? Consider pulling the left o2, disconnect the PCM, and check for continuity issues from the o2 harness to the PCM bulkhead....
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Old Aug 15, 2012 | 03:05 PM
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I checked the wires best I can when I had the car on jacks. I will try to get it on a lift next week and report back. By left side you mean driver side?

I will try the disconnect and see what happens and report back.

Thanks
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Old Aug 15, 2012 | 03:35 PM
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From: Salem/Keizer
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Originally Posted by 4U2NV-SS
I checked the wires best I can when I had the car on jacks. I will try to get it on a lift next week and report back. By left side you mean driver side?

I will try the disconnect and see what happens and report back.

Thanks
Yeah...Left being driver-side....where the problem is. My guess, is that you've got a short in one of the wires between the o2 sensor and the PCM. Purely a guess right now, but worth verifying.
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Old Aug 16, 2012 | 10:08 AM
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Thanks salemetro..


Anyone with other ideas???
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