catalytic converters Archives - UnderhoodService
Confusion, Carcasses and Catalytic Converters

Dealing with warranty return headaches starts with fixing the real problem that caused the failure to begin with.

Emissions 101: A Basic Understanding Of How Catalytic Converters Operate

To begin, an internal combustion engine creates heat energy by igniting a mixture of gasoline and atmospheric oxygen with a high-voltage spark.

VIDEO: Motor Mounts And EVAP Codes

Andrew Markel shows how an EVAP code and a catalyst efficiency code are both related to weak motor mounts. Sponsored by Auto Value and Bumper to Bumper.

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Getting the Complete Picture on Converter Efficiency

Engine ­management ­systems ­compensate for changes in engine speed, loads and temperatures by adjusting the amount of fuel injected, spark ­advance/retard and even when the intake and ­exhaust valves open. These adjustments can only do so much. Tailpipe emissions are cut further by exhaust gas recirculation (EGR) and ­secondary air injection systems. The last line

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
Using oxygen sensors to identify emissions efficiency

The ASE X1 Certification Test has a section (8 questions) focused on emissions system diagnosis. For that section, among other things, you will need to: • Identify failed catalytic converter(s); determine cause of failure; determine needed repair. • Identify failed oxygen sensor(s) (O2S/HO2S) component(s) and circuitry; determine cause of failure; determine needed repair. • Inspect

Oxygen sensors