: When installing a high flow catalytic converter on your car or truck your check engine light (CEL) may illuminate due to an increase in airflow. An oxygen sensor spacer spaces out the rear oxygen sensor from the path of exhaust gases. This tricks the vehicle's ECU into thinking that factory catalytic converter is still in place. This O2 CEL fix actually has a miniature catalytic converter built inside and will help get rid of that annoying check engine light you get after modifying your exhaust or removing your catalytic converter, and sometimes even when installing a high flow catalytic converter.Please note this CEL Fixer is not only an extension which they often do not work, this is a real mini Catalytic Converter built into it. Features: Contains a small catalyst substrate that eliminates CEL's for catalyst below efficiency.
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