air/fuel ratio Archives - UnderhoodService
LTF And STF Fuel Trim Feedback Loops

How to understand rich, lean and somewhere in between.

Diagnosing Catalytic Converter Failure Symptoms

Although construction can vary according to engine application, the common three-way catalytic converter contains a reduction and oxidation stage. To create maximum surface area, each stage is generally a ­ceramic or stainless steel honeycomb substrate covered with a rough silica and alumina wash coat. Both stages of the converter are coated with precious metal catalysts

catalytic converter diagnostics
‘5 Checks’ Recommendation Simplifies Emissions System Diagnosis, Repair

Tenneco’s Walker Emissions Control brand is helping automotive service providers simplify emissions control diagnosis and repair through a variety of new educational tools, including a recommended set of five checks to perform before installing a replacement catalytic converter. These diagnostic checks are covered in a free technical video available through the “TennecoInc” channel at YouTube.com.

5 tips