PA EMISSIONS INSPECTION EXAM
QUESTIONS AND ANSWERS 100% PASS
2026/2027
What health problems can pollution cause? - ANS Respiratory issues
What percent of air pollution is caused by vehicles? - ANS 20%
How much less air pollution do we have now than in the 1960s? (%) - ANS 98% less
What is the average thermal efficiency? (%) - ANS 20%
Where does 80% of the rest of the fuel go to? - ANS Friction, heat, and emissions
What are the 5 major pollutants? - ANS Hydrocarbons (HC), Carbon monoxide (CO), Oxides of
nitrogen (NOx), Sulfur dioxide (SO2), and particulate matter
What are hydrocarbons? - ANS Unburned fuel of carbon and hydrogen
What are hydrocarbons emitted through? - ANS Incomplete combustion and fuel evaporation
2026/2027 ALLRIGHTS RESERVED
1
, What are hydrocarbons caused by? - ANS Misfire, rich, ignition timing, engine deficiencies,
and fuel injectors
What has lowered hydrocarbons? - ANS OBD 2, component controls, fuel delivery, ignition,
emissions system, and EVAPs
Can you see or smell carbon monoxide? - ANS No
Is carbon monoxide harmful or nonharmful? - ANS Harmful
How is carbon monoxide made? - ANS Incomplete burning of fuel
What is carbon monoxide caused by?` - ANS rich, dirty air filter, fuel injectors, high fuel
pressure, defective sensors, plugged PCV valve, heat riser valve stuck open, air pump
malfunction, oil diluted with gas
How is nitrogen oxide made? - ANS Combustion of fuel at high temperatures
What is nitrogen oxide the cause of? - ANS Acid rain
What type of health issues does nitrogen oxide cause? - ANS Respiratory issues
What is nitrogen oxide caused by? - ANS lean, defective EGR, high temperature, vacuum
leaks, advance ignition timing
2026/2027 ALLRIGHTS RESERVED
2
QUESTIONS AND ANSWERS 100% PASS
2026/2027
What health problems can pollution cause? - ANS Respiratory issues
What percent of air pollution is caused by vehicles? - ANS 20%
How much less air pollution do we have now than in the 1960s? (%) - ANS 98% less
What is the average thermal efficiency? (%) - ANS 20%
Where does 80% of the rest of the fuel go to? - ANS Friction, heat, and emissions
What are the 5 major pollutants? - ANS Hydrocarbons (HC), Carbon monoxide (CO), Oxides of
nitrogen (NOx), Sulfur dioxide (SO2), and particulate matter
What are hydrocarbons? - ANS Unburned fuel of carbon and hydrogen
What are hydrocarbons emitted through? - ANS Incomplete combustion and fuel evaporation
2026/2027 ALLRIGHTS RESERVED
1
, What are hydrocarbons caused by? - ANS Misfire, rich, ignition timing, engine deficiencies,
and fuel injectors
What has lowered hydrocarbons? - ANS OBD 2, component controls, fuel delivery, ignition,
emissions system, and EVAPs
Can you see or smell carbon monoxide? - ANS No
Is carbon monoxide harmful or nonharmful? - ANS Harmful
How is carbon monoxide made? - ANS Incomplete burning of fuel
What is carbon monoxide caused by?` - ANS rich, dirty air filter, fuel injectors, high fuel
pressure, defective sensors, plugged PCV valve, heat riser valve stuck open, air pump
malfunction, oil diluted with gas
How is nitrogen oxide made? - ANS Combustion of fuel at high temperatures
What is nitrogen oxide the cause of? - ANS Acid rain
What type of health issues does nitrogen oxide cause? - ANS Respiratory issues
What is nitrogen oxide caused by? - ANS lean, defective EGR, high temperature, vacuum
leaks, advance ignition timing
2026/2027 ALLRIGHTS RESERVED
2
