Chapter 86

A catalytic converter has to be at least how hot before it starts to work?

500°F (260°C)

A P0422 (catalytic converter efficiency failure) is set. What is a possible cause? Engine mechanical fault Exhaust leak Fuel contamination Any of the above

Any of the above

A catalytic converter can be harmed by _____. Excessive engine oil Antifreeze Sulfur from poor-quality fuel Any of the above

Any of the above

The OBD-II system monitor compares the relative activity of a rear oxygen sensor to the _________________________ to determine catalytic converter efficiency.

precatalytic oxygen sensor

Catalytic converters can be tested for

restriction and for efficiency.

The catalyst materials used in a catalytic converter include

rhodium, palladium, and platinum

Which exhaust gas reading indicates a good catalytic converter?

CO is zero

What is applied to the ceramic substrate to make the surface porous?

Washcoat

Technician A says that the catalytic converter is warranted for eight years or 80,000 mi, whichever comes first. Technician B says that after replacing the catalytic converter, the old converter must be kept for possible inspection for 60 days. Which technician is correct?

Both Technicians A and B

Two technicians are discussing testing a catalytic converter. Technician A says that a vacuum gauge can be used and observed to see if the vacuum drops with the engine at 2500 RPM for 30 seconds. Technician B says that a pressure gauge can be used to check for back pressure. Which technician is correct?

Both Technicians A and B

What two primary sensors does the PCM use to check the catalytic converter?

Precat and postcat oxygen sensor

Two technicians are discussing catalytic converters. Technician A says that the exhaust mixture must be at stoictiometric for the best efficiency. Technician B says that the air-fuel mixture must be leaner than 14.7:1 for best performance from a three-way catalytic converter. Which technician is correct?

Technician A only

A catalytic converter is being tested with an infrared pyrometer. Which is an acceptable (good converter) result?

The outlet should be hotter than the inlet by 10%.

A _________________ is an element that starts a chemical reaction but is not consumed in the process.

catalyst