# 2006 Altima 3.5 headers O2 sensor bypass.



## 98_shortbed (Jun 19, 2011)

Is there a way to bypass the four O2 sensors on the motor under the exh. manifolds?? I was wondering if it was worth it to install headers and were to find a good set? I just paid off my car and its got 55,000 on it so i figure I'll do some mods, i really want to get rid of the cats and stock manifolds, exhaust will be the first thing. thank you for the help.


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## arielvtpma (Feb 14, 2006)

It is not recommended to bypass o2 sensors. better get headers for vq35de engine.


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## smj999smj (Jan 1, 2006)

Front oxygen sensors are required for the ECM in determining how much fuel to inject. Rear sensors are only monitoring sensors used to judge the efficiency of the converters. Deleting the rear sensors and/or catalytic converters will cause the MIL to illuminate due to trouble codes being set.


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## 98_shortbed (Jun 19, 2011)

Ive herd that using spark plug defoulers on the bottom O2 sensors will work and keep the Service light off, does anyone agree, may go that way, thanks for the help.


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## rallyrob (Apr 14, 2011)

on cars that have multiple O2 sensors,Eg a "primary" o2 sensor is for the engine management to use."secondary" o2 sensors are to give feedback as to the function and status of the cat converter(s).

the secondary sensors are just looking for a reduction in oxygen between the cat.So "allegedly" if the secondary sensors are placed out of direct airflow,the computer will think everything is just fine with the cat(s) even if they may not actually exist.

I've had good luck welding in a straight pipe and mounting the O2 sensor in a pipe about 3-4" long either at 90* to the exhaust flow or pointing along the direction of flow.When I say pointing along the direction of flow-the wires for the O2 sensor are angled toward the engine.Just so the sensor head doesn't have exhaust being forced at it.

kinda like this:

_____\ \_____
>>>>>>>>>>
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disclaimer:
*this modification was done on RACE only vehicles.I am in no way sponsoring or endorsing this action in any way shape or form on a road legal vehicle.I am not liable if someone applies this information to a road legal vehicle or any vehicle for that matter.*


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