# O2 sensors/LT headers



## SWGOAT (Nov 9, 2010)

Just removed stock mid pipes on my 05 could not remove front O2 sensors, siezed, purchased new O2 sensors. I am not using midpipes with cats, will I only use front O2 sensors and cap rear O2 sensors at the plug? I am installing Pacesetter LT headers and mids. Car will be dyno tuned first day out this spring, so I expect CEL. Thanks for your expertise.


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## 646904GTO (Feb 10, 2008)

You can just have the engine tuner turn off the post cat O2's. (The pre cat ones have to be on). It doesn't effect engine performance just throws a low CEL for low cat efficiency. Or you can space the sensors with spark plug spacers so the ECM only sees below threshold of 800Mv. either way it will pass OBD2 emissions. You have to have at least 5 'ready' of 7 or 7 'ready' of 9, I forget, but I know it passes.


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## svede1212 (Nov 1, 2005)

Your experience is pretty normal. The factory O2s were welded in I swear and even if you can get them out the threads will be all galled. Just plug the rear O2s, get her tuned and you should be good to go.


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