This O2 cel fix actually has a miniature catalytic converter built inside and will help 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.As a result this will throw check engine lights (Cel, , ) typically the error codes will be P0420 ( System Efficiency Threshold Bank 1) and/or P0430 P0420 System Efficiency Threshold Bank ).CEL Fix Check Engine Light Eliminator AdapterO2 Sensor for auto.New and .Type:O2 Oxygen Sensor AdapterSurface treatment: electronickellingThread: M18x1.5Length: 58mmFunction: check engine light fixColour: silverMaterial: metalSize: 58x16x25mmPackage Contents:1 * O2 Sensor Adapter ExtenderOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/1-3cm.